Malnutrition is one of the major issues associated with high mortality and morbidity in chronic dialysis patients. Several methods to evaluate the nutritional status of these patients have been attempted for example anthropome;trie measurement and biochemical parameters. Recently, it was reported that insulin-like growth factor-1 (IGF-1) has been valuable for estimating nutritional status. In this study, we measured lean body mass(LBM)by dual energy X-ray absorptiometry (DXA), IGF-1 and other biochemical parameters in 35 patients on CAPD. Two years later, the second measurement of LBM was performed, and we assessed the percent changes of LBM and biochemical parameters. There was negative correlation between the percent changes of LBM and the duration of CAPD. In patients treated with CAPD for less than 36 months (group I ) LBM increased, however, it decreased significantly in those treated for more than 36 months (group II). On the other hand, in group I there was a positive correlation between the percent changes of LBM and IGF-1. In group II there was no correlation between the percent changes of LBM and any other biochemical parameters. It could be concluded that IGF-1 is one of the predisposing factors for improving LBM of patients on CAPD for a limited duration.