OBJECTIVE: To evaluate the prognosis of patients with pathological Gleason score ≥8 after radical prostatectomy and its influencing factors. METHODS: To retrospectively analyze the clinical data of patients with prostate cancer who underwent radical prostatectomy from 2002 to 2008, with regular postoperative outpatient follow-up. Inclusion criteria: Gleason score ≥ 8 after radical surgery; no preoperative neoadjuvant endocrine therapy; complete follow-up data. Kaplan-Meier Logrank test and Cox regression were applied for univariate and multifactorial analysis to assess the factors affecting prognosis. RESULTS: Twenty-nine patients met the inclusion criteria. The mean follow-up was (51.66±25.81) months, 16 patients (55.2%) had biochemical recurrence, and the 5-year biochemical recurrence-free rate was 40.2%. 5-year tumor-specific survival rate was 95.8%, and 5-year overall survival rate was 84.8%. Univariate analysis showed that the 5-year biochemical recurrence-free rate was 75.2% in the adjuvant group, which was significantly higher than that of 0% in the group without adjuvant therapy (X2=11.514, P=0.001), and the 5-year biochemical recurrence-free rate was 100% in the adjuvant endocrine therapy combined with radiotherapy group, which was significantly higher than that of the adjuvant endocrine therapy group (60%) and the group without adjuvant therapy (0) (X2=12.369, P= 0.002). Incorporating age, preoperative PSA level, pathological Gleason score, pathological stage, incision margin and type of adjuvant therapy into a multifactorial analysis model, the results showed that the type of adjuvant therapy was a significant predictor of biochemical recurrence-free survival time after radical surgery for high-grade prostate cancer (P=0.006), and adjuvant endocrine therapy combined with radiotherapy after radical surgery significantly prolonged the time to biochemical recurrence-free survival in patients with Gleason score ≥8. The combination of adjuvant endocrine therapy after radical surgery significantly prolonged biochemical recurrence-free survival time in patients with Gleason score ≥8. CONCLUSIONS: Pathological Gleason score ≥8, high rate of positive seminal vesicle invasion and cutting edge, and early biochemical recurrence require careful selection of radical surgery. Postoperative adjuvant endocrine therapy combined with radiotherapy can significantly prolong the biochemical recurrence-free survival time.