BACKGROUND Asthma is a common health problem whose prevalence in Saudi Arabia has risen over the last few decades. Brick factories in the city of Bahrah have exacerbated the problem, and increasing numbers of asthma cases are attending local primary health care centers. OBJECTIVE Determine the risk factors of asthma in Bahrah. METHODS The study was comprised of 110 cases of bronchial asthma resident in Bahrah who were diagnosed by the treating physicians and 110 healthy controls matched in age and sex. A questionnaire was completed from cases and controls, consisting of data regarding personal, familial, indoor and outdoor environmental factors that may be potential risk factors to asthma. Bivariate and multivariate logistic regression analyses were done to assess risk factors. RESULTS The mean ages of cases and controls were 22.4 (± 16.7) and 22.8 (± 16.1) years, respectively. Each group consisted of 64 males (58%) and 46 (42%) females. There was a significant association between distance from houses to brick factories and bronchial asthma (Chi square for linear trend = 26.6, p<0.001). Multivariate logistic regression analysis showed that living within one kilometer of a brick factory (OR=5.1, CI=2.33-11.16), family history (OR=4.6, CI=2.16-9.78), allergic rhinitis (OR=3.39, CI=1.49-7.69), skin atopy (OR=4.6, CI=1.53-13.87) and recurrent respiratory tract infections (OR=4.1, CI=1.79-9.22) were independent risk factors for asthma in Bahrah. CONCLUSIONS Brick factories, family history and history of rhinitis, skin atopy, or recurrent respiratory tract infections are risk factors of bronchial asthma. An in-depth study to asses air pollution in Bahrah is recom-mended. People are advised not to live near brick factories.