OBJECTIVE Bronchiectasis not due to cystic fibrosis is usually a consequence of severe bacterial or tuberculous infection of the lungs, which is commonly seen in children in developing countries. Our aim was to study its functional sequelae and affect on work capacity in children. METHODS Seventeen children (7-17 years of age) with clinical and radiological evidence of bronchiectasis of one or both lungs were studied at the Cardiopulmonary Unit of the Tuberculosis Research Centre. Pulmonary function tests including spirometry and lung volume measurements were performed. Incremental exercise stress test was done on a treadmill, and ventilatory and cardiac parameters were monitored. Control values were taken from a previous study. RESULTS Children with bronchiectasis had lower forced vital capacity (FVC) (1.1 + 0.4 L versus 1.5 + 0.4 L, p = 0.003) and FEV1 (0.95 +/- 0.2 L versus 1.4 +/- 0.3 L, p < 0.002) compared to age- and sex-matched healthy controls. The patient group had significantly higher residual lung volumes (0.7 +/- 0.3 L versus 0.4 + 0.1 L, p < 0.02). At maximal exercise, they had lower aerobic capacity (28 +/- 6 ml/min/kg versus 38 +/- 5 ml/min/kg, p < 0.0001) and maximal ventilation (24 +/- 8 L/min versus 39 +/- 10 L/min, p < 0.001). At maximal exercise, while none of the controls desaturated, oxygen saturation fell below 88% in eight of 17 patients. CONCLUSIONS The findings show that children and adolescents with non-cystic fibrosis bronchiectasis have abnormal pulmonary function and reduced exercise capacity. This is likely to interfere with their life as well as future work capacity. Efforts should be made to minimize lung damage in childhood by ensuring early diagnosis and instituting appropriate treatment of respiratory infections.