diff --git a/backend/app/Http/Controllers/Api/CostCenterController.php b/backend/app/Http/Controllers/Api/CostCenterController.php
index 8944d2b..48b0a4d 100755
--- a/backend/app/Http/Controllers/Api/CostCenterController.php
+++ b/backend/app/Http/Controllers/Api/CostCenterController.php
@@ -209,6 +209,49 @@ public function destroy(int $id): JsonResponse
         ]);
     }
 
+    /**
+     * Atualizar palavras-chave de um centro de custo (incluindo de sistema)
+     */
+    public function updateKeywords(Request $request, int $id): JsonResponse
+    {
+        $costCenter = CostCenter::where('user_id', Auth::id())->findOrFail($id);
+
+        $validated = $request->validate([
+            'keywords' => 'required|array',
+            'keywords.*' => 'string|max:100',
+        ]);
+
+        DB::beginTransaction();
+        try {
+            // Remover antigas
+            $costCenter->keywords()->delete();
+
+            // Adicionar novas
+            foreach ($validated['keywords'] as $keyword) {
+                $costCenter->keywords()->create([
+                    'keyword' => trim($keyword),
+                    'is_case_sensitive' => false,
+                    'is_active' => true,
+                ]);
+            }
+
+            DB::commit();
+
+            return response()->json([
+                'success' => true,
+                'message' => 'Palavras-chave atualizadas com sucesso',
+                'data' => $costCenter->fresh()->load('keywords'),
+            ]);
+
+        } catch (\Exception $e) {
+            DB::rollBack();
+            return response()->json([
+                'success' => false,
+                'message' => 'Erro ao atualizar palavras-chave: ' . $e->getMessage(),
+            ], 500);
+        }
+    }
+
     /**
      * Adicionar palavra-chave a um centro de custo
      */
diff --git a/backend/routes/api.php b/backend/routes/api.php
index f67cc48..21871df 100755
--- a/backend/routes/api.php
+++ b/backend/routes/api.php
@@ -94,6 +94,7 @@
     // ============================================
     Route::apiResource('cost-centers', CostCenterController::class);
     Route::post('cost-centers/{id}/keywords', [CostCenterController::class, 'addKeyword']);
+    Route::put('cost-centers/{id}/keywords', [CostCenterController::class, 'updateKeywords']);
     Route::delete('cost-centers/{id}/keywords/{keywordId}', [CostCenterController::class, 'removeKeyword']);
     Route::post('cost-centers/match', [CostCenterController::class, 'matchByText']);
 
diff --git a/frontend/src/pages/CostCenters.jsx b/frontend/src/pages/CostCenters.jsx
index 034ec82..33327ca 100755
--- a/frontend/src/pages/CostCenters.jsx
+++ b/frontend/src/pages/CostCenters.jsx
@@ -12,9 +12,12 @@ const CostCenters = () => {
   const [loading, setLoading] = useState(true);
   const [showModal, setShowModal] = useState(false);
   const [showDeleteModal, setShowDeleteModal] = useState(false);
+  const [showKeywordsModal, setShowKeywordsModal] = useState(false);
   const [selectedItem, setSelectedItem] = useState(null);
   const [saving, setSaving] = useState(false);
   const [newKeyword, setNewKeyword] = useState('');
+  const [systemKeywords, setSystemKeywords] = useState([]);
+  const [newSystemKeyword, setNewSystemKeyword] = useState('');
   const [openDropdownId, setOpenDropdownId] = useState(null);
   const dropdownRef = useRef(null);
 
@@ -153,6 +156,58 @@ const CostCenters = () => {
     }
   };
 
+  // === Funções para gerenciar keywords de centro de custo de sistema ===
+  const handleOpenKeywordsModal = (item) => {
+    setSelectedItem(item);
+    setSystemKeywords(item.keywords?.map(k => k.keyword) || []);
+    setNewSystemKeyword('');
+    setShowKeywordsModal(true);
+  };
+
+  const handleCloseKeywordsModal = () => {
+    setShowKeywordsModal(false);
+    setSelectedItem(null);
+    setSystemKeywords([]);
+    setNewSystemKeyword('');
+  };
+
+  const handleAddSystemKeyword = () => {
+    const keyword = newSystemKeyword.trim();
+    if (keyword && !systemKeywords.includes(keyword)) {
+      setSystemKeywords(prev => [...prev, keyword]);
+      setNewSystemKeyword('');
+    }
+  };
+
+  const handleRemoveSystemKeyword = (keyword) => {
+    setSystemKeywords(prev => prev.filter(k => k !== keyword));
+  };
+
+  const handleSystemKeywordKeyPress = (e) => {
+    if (e.key === 'Enter') {
+      e.preventDefault();
+      handleAddSystemKeyword();
+    }
+  };
+
+  const handleSaveSystemKeywords = async () => {
+    if (!selectedItem) return;
+
+    setSaving(true);
+    try {
+      const response = await costCenterService.updateKeywords(selectedItem.id, systemKeywords);
+      if (response.success) {
+        toast.success(t('costCenters.keywordsUpdated') || 'Palavras-chave atualizadas com sucesso');
+        handleCloseKeywordsModal();
+        loadCostCenters();
+      }
+    } catch (error) {
+      toast.error(error.response?.data?.message || t('costCenters.keywordsError') || 'Erro ao atualizar palavras-chave');
+    } finally {
+      setSaving(false);
+    }
+  };
+
   const handleDeleteClick = (item) => {
     setSelectedItem(item);
     setShowDeleteModal(true);
@@ -267,7 +322,16 @@ const CostCenters = () => {
                         )}
                       </div>
                     </div>
-                    {!item.is_system && (
+                    {item.is_system ? (
+                      <button 
+                        className="btn btn-outline-warning btn-sm"
+                        onClick={() => handleOpenKeywordsModal(item)}
+                        title={t('costCenters.editKeywords') || 'Editar palavras-chave'}
+                      >
+                        <i className="bi bi-key me-1"></i>
+                        {t('costCenters.keywords')}
+                      </button>
+                    ) : (
                     <div className="dropdown" ref={openDropdownId === item.id ? dropdownRef : null} style={{ position: 'relative' }}>
                       <button 
                         className="btn btn-link text-slate-400 p-0" 
@@ -614,6 +678,109 @@ const CostCenters = () => {
         confirmText={t('common.delete')}
         loading={saving}
       />
+
+      {/* Modal de Edição de Keywords para Centro de Custo de Sistema */}
+      {showKeywordsModal && selectedItem && (
+        <div className="modal show d-block" style={{ backgroundColor: 'rgba(0,0,0,0.8)' }}>
+          <div className="modal-dialog modal-dialog-centered">
+            <div className="modal-content border-0" style={{ background: '#1e293b' }}>
+              <div className="modal-header border-0 pb-0">
+                <div>
+                  <h5 className="modal-title text-white mb-1">
+                    <i className="bi bi-key me-2 text-warning"></i>
+                    {t('costCenters.editKeywords') || 'Editar Palavras-chave'}
+                  </h5>
+                  <p className="text-slate-400 mb-0 small">
+                    {selectedItem.name}
+                  </p>
+                </div>
+                <button type="button" className="btn-close btn-close-white" onClick={handleCloseKeywordsModal}></button>
+              </div>
+              
+              <div className="modal-body pt-3">
+                <p className="text-slate-400 small mb-3">
+                  <i className="bi bi-info-circle me-1"></i>
+                  {t('costCenters.keywordsHelp') || 'Palavras-chave são usadas para atribuir automaticamente transações a este centro de custo.'}
+                </p>
+
+                <div className="p-3 rounded" style={{ background: '#0f172a' }}>
+                  <div className="input-group mb-3">
+                    <input
+                      type="text"
+                      className="form-control bg-dark text-white border-0"
+                      style={{ background: '#1e293b' }}
+                      value={newSystemKeyword}
+                      onChange={(e) => setNewSystemKeyword(e.target.value)}
+                      onKeyPress={handleSystemKeywordKeyPress}
+                      placeholder={t('costCenters.keywordPlaceholder') || 'Digite e pressione Enter...'}
+                    />
+                    <button 
+                      type="button" 
+                      className="btn btn-warning px-3"
+                      onClick={handleAddSystemKeyword}
+                    >
+                      <i className="bi bi-plus-lg"></i>
+                    </button>
+                  </div>
+                  
+                  <div className="d-flex flex-wrap gap-2" style={{ minHeight: '50px' }}>
+                    {systemKeywords.map((keyword, index) => (
+                      <span 
+                        key={index}
+                        className="badge d-flex align-items-center py-2 px-3"
+                        style={{ 
+                          backgroundColor: selectedItem.color + '25',
+                          color: selectedItem.color,
+                          fontSize: '0.85rem'
+                        }}
+                      >
+                        {keyword}
+                        <button
+                          type="button"
+                          className="btn-close ms-2"
+                          style={{ fontSize: '8px', filter: 'brightness(1.5)' }}
+                          onClick={() => handleRemoveSystemKeyword(keyword)}
+                        ></button>
+                      </span>
+                    ))}
+                    {systemKeywords.length === 0 && (
+                      <small className="text-slate-500 w-100 text-center py-3">
+                        <i className="bi bi-inbox me-2"></i>
+                        {t('costCenters.noKeywords') || 'Nenhuma palavra-chave definida'}
+                      </small>
+                    )}
+                  </div>
+                </div>
+              </div>
+              
+              <div className="modal-footer border-0">
+                <button type="button" className="btn btn-outline-secondary px-4" onClick={handleCloseKeywordsModal}>
+                  <i className="bi bi-x-lg me-2"></i>
+                  {t('common.cancel')}
+                </button>
+                <button 
+                  type="button" 
+                  className="btn btn-warning px-4" 
+                  onClick={handleSaveSystemKeywords}
+                  disabled={saving}
+                >
+                  {saving ? (
+                    <>
+                      <span className="spinner-border spinner-border-sm me-2"></span>
+                      {t('common.saving')}
+                    </>
+                  ) : (
+                    <>
+                      <i className="bi bi-check-lg me-2"></i>
+                      {t('common.save')}
+                    </>
+                  )}
+                </button>
+              </div>
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   );
 };
diff --git a/frontend/src/services/api.js b/frontend/src/services/api.js
index ca3c347..57d5476 100755
--- a/frontend/src/services/api.js
+++ b/frontend/src/services/api.js
@@ -212,6 +212,12 @@ export const costCenterService = {
     return response.data;
   },
 
+  // Atualizar todas as palavras-chave (inclui centros de custo de sistema)
+  updateKeywords: async (id, keywords) => {
+    const response = await api.put(`/cost-centers/${id}/keywords`, { keywords });
+    return response.data;
+  },
+
   // Remover palavra-chave
   removeKeyword: async (id, keywordId) => {
     const response = await api.delete(`/cost-centers/${id}/keywords/${keywordId}`);