BACKGROUND: Dietary folate has been inversely related to the risk of several cancers. However, studies on the role of dietary folate in oesophageal cancer are scanty. PATIENTS AND METHODS: Using data from a multicentric case-control study conducted in Italy and Switzerland between 1992 and 1999, we investigated the association between dietary folate intake and oesophageal squamous-cell carcinoma (OSCC) among 351 men with incident, histologically confirmed OSCC and 875 hospital controls admitted for acute, non-neoplastic conditions, unrelated to alcohol and smoking consumption. Intake of folate and other nutrients was computed from a validated food frequency questionnaire. RESULTS: The multivariate odds ratios (ORs) of OSCC were 0.68 (95% confidence intervals, CI: 0.46-1.00) for the highest versus the lowest tertile of folate intake, and 0.84 (95% CI: 0.72-0.99) for an increment of folate intake equal to a standard deviation (98 microg/day). The inverse relation was somewhat stronger in strata of high methionine, vitamin B6 and alcohol intake, and did not vary substantially according to age and smoking habits. CONCLUSION: Dietary folate was inversely related to OSCC risk in this population with high alcohol consumption and infrequent use of supplements and multivitamins. [Authors]