Muscle wasting is independent predictor of mortality in end-stage renal disease (ESRD) patients on maintenance hemodialysis (MHD). We investigated the effect of insulin resistance on lean body mass (LBM), and association between insulin resistance, chronic inflammation, and body composition in these patients. We analyzed cross-sectionally body composition, nutritional status and biochemical parameters in 35 non-diabetic ESRD patients who were on MHD. Bioelectrical impedance analysis was performed to quantify body fat, lean body mass and total body water (FAT (%), FAT (kg), LBM (%), LBM (kg) and TBW(%)). The association between LBM (kg) and gender, FAT (kg), high sensitivity C-reactive protein (hs-CRP), and homeostatic model assessment score (HOMA-IR) was recorded. Multiple linear regression analysis using LBM (kg) as dependent variable showed that FAT (kg) (beta = 0.563, p = 0.05), HOMA-IR (beta = 0.619, p = 0.03), and hs-CRP (beta = 0.488, p = 0.04) were independently associated with LBM in males. In females, only FAT (kg) (beta = 0.648, p = 0.001) significantly predicted LBM. Those variables explained 37% of variance of LBM (kg) in males, and 44% in females. It seems that insulin resistance participates independently in the pathogenesis of muscle wasting in both sexes, particularly in males. The effect of chronic inflammation was not so strong in females, and this point out that regulation of muscle wasting in female patients probably differs from that in males.