Objectives: We compared the Gleason scores obtained from sextant prostate biopsy and radical prostatectomy (RP) specimens in patients with localized prostate cancer. Patients and Methods: Sixty-one patients having a clinical diagnosis of localized prostate cancer underwent needle biopsy under transrectal ultrasonography (TRUS) and RP. Grading and staging were assigned based on Gleason scores and the TNM system, respectively. Results: Mean patient age was 65.5 +/- 13.43 years and mean PSA level was 14.69 +/- 3.95. Mean Gleason score for prostate biopsy and RP specimen were 5.85 +/- 0.7 and 6.34 +/- 1.44, respectively. With respect to clinical stage, there were 20 patients in stage 1 and 41 patients in stage 2 prostate cancer. Comparing the Gleason scores, the biopsy score was lower in 26 (42.26%) and higher than RP specimens in 7 (11.84%) cases, and there was agreement between the biopsy and RP specimens in 28 (45.9%) patients. The difference between the two Gleason scores was +/- 1 for 18 patients (29.5%) and +/- 2 or more for 17 patients (27.86%). Conclusion: In our study, high Gleason score biopsies with elevated PSA level (> 10 ng/ml) were risk factors for extraprostatic extension, and we demonstrated that Gleason scores were significantly correlated with seminal vesicle and lymph node invasion (p < 0.05). The Gleason scores of biopsy and RP specimens agreed with 45.9% of TRUS-guided sextant prostate biopsies, and this ratio was 91.1% in moderately differentiated tumors Copyright (C) 2001 S. Karger AG, Basel.