In this study, the authors investigated the possible relationship between environmental-including dietary-factors and respiratory and ear infections in children. A sample of 304 children, aged 4-5 y, in Geneva, Switzerland, was studied. Mothers filled out a questionnaire that the authors provided. The questionnaire included items on food frequency, infections, and background factors (e.g., education, housing conditions, parents' smoking habits). Allergy was a risk factor for all infections, and mother's age was a protective factor. Humid conditions at home was a significant risk factor for cold, sore throat, and otitis (odds ratios = 2.71, 3.03, and 2.77, respectively); mold in the home was a significant risk factor for otitis (odds ratio = 2.80); and attending day-care centers was a significant risk factor for cold and bronchitis (odds ratios = 1.36 and 1.89, respectively). Dietary factors were not related to disease risk nor were environmental tobacco smoke or housing conditions generally related to an increased risk.