This study was performed to determine risk factors associated with osteoporosis that develops after renal transplantation. Sixty-five kidney graft recipients were included in this study. They were divided into four groups according to the time since transplantation: Group 1 (< 1 year; n = 26), group 2 (1-3 years; n = 16), group 3 (3-5 years; n = 12) and group 4 (> 5 years; n = 11). These groups were matched according to probable risk factors for osteoporosis, findings of serum biochemistry, biochemical markers of bone turnover and measurements of bone mineral density. One way ANOVA test and Kruskal-Wallis test were used for statistical analysis. Osteoporosis was found in 22 recipients (33.8%). There were significant differences in recipient age, cumulative steroid dose, and episodes of acute rejection between the four groups. Increasing age, cumulative steroid dose and episodes of acute rejection were found to be risk factors for osteoporosis in our study.