Histopathological grading of prostate cancer (PCa) is associated with significant interobserver variability. This, as well as clinical consequences of histopathological re-evaluation, was investigated. In 350 patients, histopathological re-evaluations of prostate biopsies were compared with primary pathology reports and with histopathology of the radical prostatectomy specimen. The consequences of re-evaluation for clinical workup and treatment of patients according to local algorithms were determined. For Gleason score (GS), complete agreement between primary report and re-evaluation was found in 76.9%. The cancers were assessed with higher GS at re-evaluation in 25.0% of patients in cases with primary GS ≤ 6, while scores were devaluated in 3.0% and 10.3% of the patients with primary GS = 7 and ≥ 8, respectively. Strategies for clinical evaluation and treatment were changed as a result of the biopsy re-evaluations in 19.7% and 13.1% of patients, respectively. Gleason scoring based on the radical prostatectomy specimen was higher than in both primary reports and re-evaluation of biopsies. Although a relatively high degree of concordance was found between biopsy assessments, the significant trend towards higher Gleason scoring at re-evaluation, leading to frequent changes in clinical assessments and surgical strategy, justifies re-evaluation of PCa biopsies in patients with primary GS ≤ 6.