We compared the prostate-specific antigen density (PSAD) in clinically and surgically staged patients with specimen-confined prostate cancer (n = 57) and in patients with benign hyperplasia (n = 69), who underwent transvesical adenomectomy. The PSAD was calculated from the preoperative PSA level and the specimen volume. The prostate volume was determined by dividing the prostate weight by the specific gravity of the tissue. The mean tissue values used for PSAD calculation were 51.9 g in men with prostate cancer (PCA) and 62.9 g in men with benign prostatic hyperplasia (BPH). The PSAD values showed significant differences (BPH 0.19 versus PCA 0.37, P = 0.029). Receiver operator characteristic (ROC) curves demonstrated the best cutoff value to be 0.15, with the sensitivity being 58%; the specificity, 51% and the positive predictive value of PCA, 49%. At a serum PSA level below 10ng/ml, the best cutoff value was 0.1 and the positive predictive value was 51%. The PSAD results we calculated from an accurate prostate volume (surgical estimate) show that PSAD is not a significant predictor of prostate cancer.