We investigate the familial and environmental risk factors associated with asthma among United Arab Emirates schoolchildren aged 6-14 years. A cross-sectional study of 850 schoolchildren living in both urban and rural areas (average age 9.36 +/- 2.11 years; 46.8% boys, 53.2% girls) was conducted using self-administered questionnaires between October 1992 and May 1993. The population sample had a high prevalence rate of diagnosed asthma (13.6%) and allergic rhinitis (22.9%). The frequency of asthma, allergic rhinitis, and eczema among parents and siblings reflected the same pattern as that seen in the children. Environmental risk factors associated with asthma were pets, medicine, plants, dust storm, physical exercise, humidity, and perfume. All other factors, such as foods, climate, and parental smoking, showed no apparent relation to the development of asthma. The logistic regression analysis showed that parental asthma, plants, perfume, dust storm, humidity, and pets were the only significant predictors after adjusting for sex and other confounding covariates in the model. In conclusion, risk factors for asthma identified by our study are similar to those found in other community-based studies. Consistencies and discrepancies between our findings and those from other studies with respect to asthma risk factors support the hypothesis that asthma is a multifactorial disease related to both familial and environmental influences.