Background and aims: Insulin-like growth factor-I (IGF-I) and leptin are known to be involved in the regulation of body weight and body composition. Age dependent changes in body composition, and the interactions with serum leptin and IGF-I levels have not been evaluated in boxers previously. Therefore we investigated anthropometric and body composition variables in active boxers and retired amateur boxers. Additionally serum IGF-I and leptin levels were determined. Methods: Thirty actively competing or retired boxers (young team: 10, adult team: 10, retired boxers (trainer): 10) and 15 sex-matched healthy non-boxing controls were included in the study. Body composition variables including fat ratio (976), fat mass (kg), abdominal fat ratio (016) and abdominal fat mass (kg), were determined by bioelectrical impedance analyzer Results: Body composition variables and serum leptin level were significantly higher in the retired boxer group when compared to young team and adult team (p<0.05). However, in retired boxers mean IGF-I level was significantly lower than young team and adult team (p<0.05). In boxers there were significant negative correlations between IGF-I vs BMI, waist circumference, fat ratio, fat mass, abdominal fat ratio and abdominal fat mass (p<0.05). Conclusions: Present study demonstrated for the first time that waist circumference, fat ratio,fat mass, abdominal fat ratio, abdominal fat mass and serum leptin level were significanly high, and IGF-I level was significantly low in retired boxers. These data suggest that low IGF-I level in retired boxers could be the cause of impaired anthropometric and body composition parameters. It is tempting to speculate that retired boxers are at risk for cardiovascular complications, and evaluation of cardiovascular risk factors is necessary.