Objective. The purpose of this study was to investigate the effect of immunosuppressants on the incidence of and risk factors for symptomatic benign prostatic hyperplasia (BPH) in relative-donor kidney transplant recipients. Material and methods. A retrospective cohort study was performed to determine the incidence of symptomatic BPH in kidney transplant recipients according to standard diagnostic criteria, the expression levels of keratinocyte growth factor, transforming growth factor-beta (TGF-beta) and serum testosterone, and the CD4/CD8 ratio in T lymphocytes. Results. The incidence of symptomatic BPH (50-59-year-old group, p = 0.010; 60-69-year-old group, p = 0.004; >= 70-year-old group, p = 0.032), testosterone level (50-59-year-old group, p = 0.045; 60-69-year-old group, p = 0.035; >= 70-year-old group, p = 0.041) and the CD4/CD8 ratio (50-59-year-old group, p = 0.013; 60-69-year-old group, p = 0.010; >= 70-year-old group, p = 0.015) of kidney transplant recipients with long-term calcineurin inhibitor (CNI) and prednisone use were all lower than those values in a normal group that had not received transplants. The TGF-beta (p < 0.001) expression level was higher in kidney transplant recipients than in the non-transplant group, and the keratinocyte growth factor expression level was not statistically different between the kidney transplant recipients and the non-transplant group. Conclusions. Kidney transplant recipients with long-term CNI and prednisone use may have a low incidence of symptomatic BPH, which may be related to TGF-beta and keratinocyte growth factor expression, testosterone levels and lymphocyte infiltration. Further high-quality prospective studies are needed to confirm these conclusions.