We examined whether the tumor volume (TV) is a good predictor of PSA recurrence after radical prostatectomy. Data were collected for 158 patients with clinically localized prostate cancer undergoing radical prostatectomy without neoadjuvant hormonal therapy in our hospital since April 2005 to September 2007. Along with the routine pathological assessment, TV was assessed in all prostatectomy specimens. PSA recurrence was defined as PSA levels of greater than 0.2 ng/ml. The TVs were 1.81+/-1.66 ml (mean +/-SD) ranging from 0.02 to 8.20 ml. The TV in cT1c was 1.77+/-1.64, and 1.89+/-1.72 ml in cT2 (not significant). Significant differences were observed between TV and pT. The TVs in pT2a, pT2b and pT3/4 were 0.54+/-0.54, 1.63+/-1.47 and 2.67+/-1.80 ml, respectively. The median follow-up period was 32.3 months (range from 15 to 45) after radical prostatectomy, and PSA recurrence was observed in 32 cases. Patients with smaller TV (TV <1.3 ml) had a higher PSA-free survival rate (89.5%) than those with a larger TV (TV > or = 1.3 ml, 66.7%) with a significant difference atp <0.001 (log-rank test). A multivariate analysis was performed for PSA, TV, pT, Gleason Score (GS), and surgical margins. Significant differences were observed for GS, and surgical margins, but not for TV. Clinically organ-confined disease in Japanese patients with prostate cancer included various cancers from clinically insignificant to locally advanced ones. In our series, TV was not regarded as a predictor of PSA recurrence after radical prostatectomy.