A phase II study was performed to assess the efficacy and toxicity of the combination of 5-fluorouracil (5-FU), leucovorin (LV), etoposide, and cisplatin (FLEP) in patients with advanced gastric carcinoma. A total of 46 consecutive, previously untreated patients with unresectable, measurable gastric carcinoma were treated with 300 mg/m2 LV, 100 mg/m2 etoposide, 500 mg/m2 5-FU, and 30 mg/m2 cisplatin on days 1-3 every 28 days. All courses were given on an outpatient basis. A total of 169 courses of treatment were given. In all, 18 of the 46 patients (39%) had an objective response [95% confidence interval (CI), 25%-54%] and 2 (4%) patients experienced a clinical complete response. The median duration of response was 5 months. The main side effects were hematological and gastrointestinal. Grade 3-4 toxicity was encountered as follows: leukopenia, in 9.5% of the courses; anemia, in 3%; thrombocytopenia, in 3%; nausea/vomiting, in 4%; and diarrhea, in 5%. Hospitalization due to fever and granulocytopenia was required in 5 patients, 3 of whom died of sepsis. In conclusion, FLEP shows moderate activity in patients with advanced gastric carcinoma, albeit at the cost of a high degree of toxicity. For this reason we do not recommend its use.