To examine the relationship between colon cancer and food groups from vegetable or animal sources and their possible interactions with gender, we analyzed data from a Dutch case-control study. Dietary patterns were assessed for 232 colon cancer cases and 259 population controls. In multivariate analyses, the consumption of vegetables was associated significantly with reduced colon-cancer risk (odds ratio [OR] for highest cf lowest quartile of consumption = 0.4, 95 percent confidence interval [CI] = 0.2-0.7, P-trend = 0.0004). Consumption of fresh red meat was associated positively with risk in women (OR = 2.4, 95% CI = 1.0-5.7, P-trend = 0.04), especially for those with a high consumption of red meat relative to the consumption of vegetables and fruits (OR = 3.1). For men, no association with consumption of fresh red meat was found (OR = 0.9). No clear associations were found for other products of vegetable or animal origin. The results of this Dutch case-control study support the preventive potential of a high-vegetable diet in colon cancer risk. This study suggest this may be important for women consuming a diet high in red meat.