Cisplatin (P) and 5-fluorouracil (5FU) have demonstrated activity for the treatment of squamous cell carcinoma of the esophagus. Previous studies have shown that leucovorin (L) may potentiate the antitumoral activity of 5FU, so we tested the combination P-5FU-L in 31 patients with inoperable squamous cell esophageal carcinoma. Chemotherapy consisted of P 20 mg/m2 in 4 h, followed by L 200 mg/m2 in 2 h and 5FU 600 mg/m2 in 18 h. This schedule was repeated for 5 days every 4 weeks. The treatment plan included three courses of chemotherapy followed by radiotherapy. The overall response rate was 58% (95% CI = 39-76%), with one complete remission (3%), and 61% of patients reported an improvement in dysphagia. Gastrointestinal toxicity was the main side effect: grade 3-4 mucositis appeared in 19% of patients, grade 3-4 nausea/vomiting in 13%, and grade 3-4 diarrhea in 6.5%. There was one toxic death caused by neutropenia and sepsis. Nineteen patients received local radiotherapy after chemotherapy, which increased the overall response rate to 63% (5% complete responses). Dysphagia improved in 75% of them. The median survival for all patients was 11 months. This study shows that sequential therapy with P-5FU-L and radiotherapy achieves a high response rate as well as adequate symptomatic relief in patients with inoperable esophageal cancer. The results justify further evaluation of P-5FU-L in patients with earlier-stage disease.