Bronchial asthma is one of the most common illnesses in children. Factors influencing development of asthma have not been studied in rural population. 2000 school going children from five schools of Chhainsa and Dayalpur Primary Health Centre area in Ballabgarh Block of Haryana state were screened for presence of symptoms of asthma using a questionnaire suggested by International Study of Asthma and Allergy in Children (ISSAC). 40 children were identified as cases of bronchial asthma. For each child with asthma two age and sex matched non-asthmatic controls were selected from the study population. History, clinical examination and in-depth interview were carried out for all cases and controls. Factors associated with presence of symptoms of asthma on multivariate analysis were passive smoking (OR 3.33, 95% CI 1.85-7.65), pets at home (OR 5.5, 95% CI 1.04-29.15), and absence of windows in living rooms (OR 4.03, 95% CI 1.17-13.79). Factors such as family history of asthma, history of worm infestation, fuel used for cooking, location of kitchen and food allergy were not significant on statistical analysis. Thus, passive smoking, inadequate ventilation and pets (dogs and cats) at home are significant risk factors associated with presence of symptoms of asthma in rural children.