It has long been suggested that a varied diet may protect against gastric cancer, in the absence, however, of definition and quantification of the issue. Thus, we considered the relationship between diet diversity (i.e., variety of food intake computed as the total number of foods consumed at least once per week) and the risk of gastric cancer using data of a case-control study conducted between 1985 and 1993 in northern Italy on 746 gastric-cancer cases below age 75 years and 2,053 controls admitted to hospital for acute, non-neoplastic, non-digestive-tract diseases. A significant inverse association was observed between various measures of food diversity and gastric cancer risk. Compared with subjects in the lowest quartile of total diversity, the multivariate odds ratios (ORs) were 0.9 for the second, 0.9 for the third and 0.7 for the highest quartiles. The inverse association was even stronger for vegetable (OR = 0.5 for the highest level) and fruit (OR = 0.6) diversity. Our findings were not explained by allowance for total calorie intake and total number of servings, besides education as an indicator of social class, and support, therefore, the concept that a more diversified and richer diet is a relevant underlying correlate of the decline in gastric cancer rates.