Clinical nutritional status and physical work capacity at submaximal level were assessed in 96 rural Hyderbad boys, 14 to 17 years of age. Data available on the previous nutritional status of these children when they were 5 years of age were used for classifying them into different nutritional grades. Factors responsible for undernutrition childhood continued to operate on later growth. Both height and weight at 5 years correlated well (P less than 0.001) with current height and weight. About 64% (P less than 0.001) of the variation in physical work capacity at a heart rate of 170/min (physical work capacity 170 kpm/min) could be explained by the differences in current body weight; habitual physical activity explained another 10% (P less than 0.001) of the variation. Malnutrition in early childhood continuing into adolescence could be considered to have adversely affected their work capacity by influencing their body weight. However, even severe undernutrition during childhood had no effect on work performance, when expressed in terms of unit weight. But for the same work load, undernourished subjects had to use significantly higher heart rate at moderate work level as compared to their counterparts.