The occurrence of asthma and allergy are related to lifestyle factors, and dietary pattern may be one of the contributing factors. To examine the possible association between dietary intake and the prevalence of asthma and allergic rhinitis in teenagers. In a population-based cross-sectional survey, the relationship was sought between food frequency and physician-diagnosed asthma and allergic rhinitis in 1166 adolescents aged 13-17. The prevalence was 4.0% for asthma and 12.4% for rhinitis. Living in an urbanized area was a significant predictor of asthma and rhinitis. In univariate analysis, higher frequencies of oily fish, butcher's meat, liver and deep-fried foods were associated with asthma. Relevant food frequency variables were dichotomized at the 75th percentile for multivariate logistic regression analysis, which included adjustment for two levels of urbanization. Asthma was associated with intakes of liver (OR = 2.32, 95%CI 1.11-4.80), deep-fried foods (OR = 2.13, 95%CI 1.06-4.30) and butcher's meat (OR 1.84, 95%CI 0.89-3.80). In a similar analysis, allergic rhinitis was associated with liver (OR = 1.67, 95%CI 1.06-2.63). No protective effect was demonstrated for any of the food items examined. Protein-rich and fat-rich foods of animal origin were associated with a higher prevalence of asthma in teenagers.