Introduction: Accidental ingestion of caustic substances may cause serious problems in children. Approximately 20% of caustic ingestions result in esophageal stricture formation, resulting from excessive collagen synthesis to the extracellular matrix by fibroblasts. Recent studies showed that a single application of 5-fluorouracil (5-FU) is a very effective inhibitor of fibroblast proliferation and differentiation for prolonged periods. Using an experimental model, we investigated the efficacy of single-dose 5-FU on stricture formation after caustic esophageal burn.