Using cross-sectional data of an epidemiological study, risk factors for asthma and recurrent wheezy bronchitis were investigated in 1812 primary school children. Children with asthma (n = 63) had a similar pattern but a higher frequency of chronic respiratory symptoms than those with recurrent wheezy bronchitis (n = 136). Logistic regression analyses showed similar risk factors for both disorders, however, more pronounced for asthma. Prematurity was a significant risk factor for asthma and for recurrent wheezy bronchitis. Children with asthma more often had a family history of paternal or maternal asthma and their mothers tended to be younger. Effects of paternal asthma and prematurity were also found when the atopic status of the child (defined as skin test positivity to any of seven aero allergens) was taken into account. Next to genetic effects, adverse circumstances in early life seem to be important for the development of asthma. In school children recurrent wheezy bronchitis and asthma seem to be similar disorders which differ in quantitative but not qualitative aspects.