OBJECTIVE To investigate the efficiency and safety of the oxaliplatin, fluorouracil(5-FU)and leucovorin regimen(FOLFOX)in previously untreated patients with metastatic or recurrent colorectal cancer. METHODS Previously untreated patients with metastatic or recurrent colorectal cancer received 100 mg/m2 of oxaliplatin intravenously(IV)over 2 h on day 1,and IV 400 mg/m2 of leucovorin over 2 h followed by a bolus of 400 mg/m2 of 5-FU.Then 2,600;,000 mg/m2 of 5-FU was administered by continuous infusion over 46 h. RESULTS An evaluated response rate was determined for 97 of 105 treated patients.The overal response rate was 35.1%,9 patients(9.3%) had a complete response and 25 patients(25.8%)a partial response.Thirty-two patients(33.0%)developed stable disease and 32.0%of the patients progressed.The median time to progression(TTP)was 7.7 months and the median overal survival 20.5 months.One and 2-year survival rates were 68%and 32%.Toxic effects based on the National Cancer Institute-Common Toxicity Criteria(NCI-CTC),reaching grade 3/4 were:neutropenia 12.3%, anemia 11.3%,vomiting 4.1%and diarrhea 7.2%.Grade 3 neuropathy was 5.1%.The overall survival rate of patients who had received a radical resection was superior to the patients who had not received a operation,or had received a pal iative resection(P=0.0658).The serum levels of CEA,ALP and LDH had no relationship with survival(P>0.05). CONCLUSION The FOLFOX regimen containing oxaliplatin,5-FU plus leucovorin was an efficacious regimen with good tolerability in previously untreated metastatic or recurrent colorectal cancer patients.