Prostate cancer antigen 3 (PCA3) is a biomarker for diagnosing prostate cancer (PCa) identified in the Caucasian population. We evaluated the effectiveness of urinary PCA3 in predicting the biopsy result in 500 men undergoing initial prostate biopsy. The predictive power of the PCA3 score was evaluated by the area under receiver operating characteristic (ROC) curve (AUC) and by decision curve analysis. PCA3 score sufficed to discriminate positive from negative prostate biopsy results but was not correlated with the aggressiveness of PCa. The ROC analysis showed a higher AUC for the PCA3 score than %fPSA (0.750 vs 0.622, P = 0.046) in patients with a PSA of 4.0-10.0 ng ml-1 , but the PCA3-based model is not significantly better than the base model. Decision curve analysis indicates the PCA3-based model was superior to the base model with a higher net benefit for almost all threshold probabilities, especially the threshold probabilities of 25%-40% in patients with a PSA of 4.0-10.0 ng ml-1 . However, the AUC of the PCA3 score (0.712) is not superior to %fPSA (0.698) or PSAD (0.773) in patients with a PSA >10.0 ng ml-1 . Our results confirmed that the RT-PCR-based PCA3 test moderately improved diagnostic accuracy in Chinese patients undergoing first prostate biopsy with a PSA of 4.0-10.0 ng ml-1 .