Respiratory syncytial virus (RSV) is the most important agent causing respiratory illness in the young paediatric age group. OBJECTIVE To determine the clinical profile and risk factors for respiratory distress in young Malaysian children with RSV infection. METHODS The study was a retrospective review of 185 children below the age of 24 months hospitalised with RSV infection. Respiratory distress at admission was categorised into mild, moderate and severe using a modified respiratory distress assessment instrument (RDAI) score. RESULTS RSV infection occurred most frequently in the 3-6 months age group with a male predominance. A small number of patients had extrapulmonary symptoms of diarrhoea (8%) and seizures (7%). Forty-seven patients (25%) had an underlying illness. The majority of patients (63%) had mild respiratory distress. All patients (8%) with severe respiratory distress required intensive care and 80% of them required assisted ventilation. The overall mean duration of hospital stay was 7.0 +/- 5.0 days. There was only one death. Risk factors associated with respiratory distress included age less than 3 months, a family history of bronchial asthma and presence of an underlying disease. CONCLUSIONS The majority of Malaysian children with RSV infection had a mild illness but a small number of them who developed severe illness had a higher incidence of respiratory failure requiring assisted ventilation.