We undertook a prospective study to evaluate the effects of hemodialysis on serum prostate-specific antigen (PSA) in 26 male patients with end-stage renal disease as a clinical model for assessing the role of the kidney in PSA clearance. Patients ranging in age from fifty-one to eighty-three years (mean 64.8 years) underwent phlebotomy immediately before and after outpatient hemodialysis on a Monday/Wednesday/Friday or Tuesday/Thursday/Saturday schedule, with serum PSA values determined by the Abbott IMX Microparticle Enzyme Immunoassay. The mean +/- standard deviation for all post-dialysis PSA levels, 2.43 +/- 3.74, was significantly greater than that for pre-dialysis levels, 2.11 +/- 3.19 (p = 0.04). However, no statistically significant differences were found on comparing the combined pre- and post-dialysis PSA values over the course of the study (p = 0.2733) or when sequential pre-dialysis (p = 0.28) and post-dialysis (p = 0.92) levels were analyzed separately. We conclude that PSA is not eliminated by hemodialysis, and our results infer that it is not cleared by renal mechanisms.