OBJECTIVE: The authors describe and evaluate epidemiological and clinical features of asthmatic outpatients attending a specialized pediatric unit. METHODS: Asthmatic patients of the Allergy and Immunology Unit of Department of Pediatrics (University of São Paulo) followed in the period from 1988 up to 1995 were evaluated in a non-randomized and retrospective study. The patients were submitted to a protocol for associated diseases (gastroesophageal reflux, toxocariasis, tuberculosis, immunodeficiencies and other atopic diseases). Asthma severity was classified according to the 1st Brazilian Consensus for Asthma Management. RESULTS: 237 patients (128M:109F) were admitted with mean age of 86 months. The first episode of wheezing occurred during the first year in 56% of them. Parental history of atopy was present in 61.6%. 53% of the patients had severe asthma in the first evaluation and it decreased for 35% at the time of this protocol. Cold weather (78.3%) and house dust (64.7%) were the commonest triggering factors. The following associated diseases were diagnosed: gastroesophageal reflux (n=57), toxocariasis (n=17), tuberculosis (n=7) and immunodeficiencies (n=16). 90.2% had other atopic conditions.CONCLUSION: The authors emphasize that the first asthmatic episode occurred earlier but there is a delay in sending the patients to specialized centers. The evaluation of clinical and epidemiological findings besides familial history are necessary for adequate treatment and early introduction of prophylactic measures.