BACKGROUND: Prostate cancer is the most common malignant tumor among adult men worldwide andthe second most common cause of cancer death. Gleason grading system is a powerful predictor in theprognosis and treatment outcome of prostate carcinoma. OBJECTIVE: This retrospective study aims to evaluate the accuracy of transrectal ultrasound (TRUS)-guided biopsy of the prostate compared to radical prostatectomy specimen in predicting thepathological grading of prostate adenocarcinoma using the Gleason scores between specimens. METHODS: This is a review of 69 patients who underwent radical prostatectomy due to prostate cancerin 2010-2015. The Gleason scores of the transrectal ultrasound biopsies were compared with thesurgical specimen. RESULTS: The biopsy Gleason scores obtained from the TRUS biopsy and the radical prostatectomyspecimens were similar in 79.7% of the cases. In patients with moderately differentiated tumors onbiopsy (Gleason score of 5 to 7), the concordance rate was 83% with upgrading after surgery in 16%of the cases. In poorly-differentiated tumors on biopsy (Gleason score of 8 to 10), 74% revealed thesame score on histopathological examination after radical prostatectomy, while 25% of the caseswere given lower Gleason scores after operation. Overall, 20.3% cases were discrepant by 1 or moreGleason scores after radical prostatectomy. There was a good histopathological correlation betweenTRUS biopsy and prostatectomy specimen {AUC =0.787(p=0.001)}. CONCLUSION The overall accuracy of Gleason score on transrectal ultrasound-guided biopsies inpredicting prostatectomy specimen grade is favorable. It plays a significant role in clinical decisionmaking of patients with prostate carcinoma.