The aim of the study was to investigate the potential relationship between left ventricular hypertrophy (LVH) and left ventricular ejection fraction with serum leptin in end-stage renal failure patients undergoing regular hemodialysis (HD) treatment. A cross-sectional study was carried out on 41 patients (15 women, 26 men) with end-stage renal disease (ESRD), undergoing maintenance HD treatment with acetate basis dialysate and polysulfone membranes. Serum leptin, pre- and post-dialysis creatinine, predialysis BUN, calcium (Ca), phosphorus (P), serum albumin (Alb) and serum ferritin were monitorized; the patients were categorized into no LVH, mild , moderate and severe LVH, according to the performed echocardiographies. The mean patient's age was 46+/-17.6 years. The mean length of the time patients had received HD was 29.5+/-34 months (median: 18 months). The mean serum leptin was 9.5+/-13.8 ng/mL (median value 4.7 ng/mL). In this study no significant association between stages of LVH with serum leptin was seen. In this study a significant positive correlation between LV ejection fraction with logarithm of serum leptin (r=0.32, P=0.048) (adjusted for age, duration and doses of dialysis, BMI, diabetes mellitus, serum ferritin, Ca, P and serum Alb was observed). Leptin might not be an aggravator for LV hypertrophy. This behavior of leptin in maintenance HD patients which is in contrast to general population, especially in obese patients with normal renal function could be explained through its reverse epidemiology role in HD patients. Our results emphasize the importance of leptin in HD and clinical impact of these findings merit further investigation.