In order to examine the relationship between dietary sucrose intake and colorectal cancer, a case-control study was conducted in Uruguay in the time period 1992-1996. In all, 289 cases and 564 controls, admitted for diagnosis or treatment in the 4 major hospitals in Montevideo, were considered eligible for the study. Total sucrose intake was associated with a monotonic positive gradient of risks and the odds ratio (OR) for the uppermost quartile of intake was of 2.18 (95% confidence interval, CI, 1.35-3.51). Glucose intake was associated with a small and non-significant increase in risk (OR 1.46, 95% CI 0.76-2.82). Finally, an interaction between sucrose and protein intake was found, and the OR for high intakes of sucrose and protein was 6.07.