<strong>BACKGROUND</strong> Being overweight for kidney transplant recipients can cause serious side effects. Weight gain affects two-thirds of kidney transplant recipients and has been attributed to a more liberal diet after transplantation, recovery of appetite due to lack of uremic toxicity, corticosteroid use, and inadequate lifestyle changes. The aim of this study was to assess gender-dependent profile of body mass index (BMI) changes after kidney transplantation (KTx). <strong>MATERIAL AND METHODS</strong> Sixty-two kidney transplant recipients (38 males and 24 females), aged 46.0±12.8 years at KTx, were observed according to weight gain after KTx. BMI was calculated before transplantation (pre-KTx) and at 6, 12, and 24 months post-KTx. <strong>RESULTS</strong> During the 24-month observation period, we found an increase in the incidence of kidney transplant recipients being overweight or obese (pre-KTx 43.5% increase and 24-month post-Ktx 61.3% increase, P=0.036). We analyzed a number of factors that could potentially influence a 24-month BMI gain including age at KTx, gender, pre-KTx BMI, time on dialysis, pre-KTx glucose metabolism disorder, and post-KTx diabetes mellitus. For female recipients, there was a significant step-wise post-KTx increase in BMI during the 24-month observation period. The overall pre-KTx to 24-month net increase for female BMI was 2 times greater than that observed for male recipients (1.90±2.20 kg/m² versus 0.89±1.85 kg/m², P<0.001). <strong>CONCLUSIONS</strong> Weight gain after KTx was observed in both sexes, but the net BMI increase was more than 2 times greater in females than in males at 24-months post-KTx. This indicated the need for diet education and strict weight control in kidney transplant recipients, especially in female patients.