The present study was undertaken to investigate the predictors in patients who received hormonal therapy (HT) for prostate-specific antigen recurrence (PSAR) after surgery. Predictors for the progression-free survival were assessed in 55 patients who received HT for PSAR after surgery. In multivariate analysis, primary Gleason grade > or =4 and PSA doubling time (PSA-DT) <6 months were independent predictors. The patients were stratified into low-risk group (Gleason grade <4 and PSA-DT > or =6), high-risk group (Gleason grade > or =4 and PSA-DT <6) and intermediate-risk group (all others). In the intermediate- and high-risk groups, progression-free survival rate was significantly higher in patients with PSA level <2 than in those with PSA level > or =2 at the initiation of HT. Primary Gleason grade > or =4 and PSA-DT <6 months are independent predictors. Patients in the intermediate- and high-risk groups may benefit from early HT for PSAR after surgery.