The dietary pattern of a population sample of males selected as a control group for a case-control study on bladder cancer carried out in four different regions of Spain is presented. Out of 807 population controls initially selected, 530 were interviewed, 465 males and 65 females. The method of selection of the study subjects and the diet assessment method are described. Our results confirm the Mediterranean pattern of the Spanish diet, with an important consumption of fresh fish, fruits and vegetables, and the use of vegetable oils, specially olive oil, for cooking and seasoning, accompanied with a high polyunsaturated/saturated ratio (0.7). The consumption of butter, cheese and other dairy products, on the other hand, is very low. Estimated total caloric intake is relatively low if compared with international figures, although questionnaire base assessment may seriously underestimate caloric intake, as it is the absolute amount of intake of lipids and carbohydrates. In relative terms, however, lipids provide the highest percentage of calories.