OBJECTIVE To report the results of the simultaneous inguinal hernia repair during radical retropubic prostatectomy (RRP) with the preperitoneal tension-free Stoppa technique, using a polypropylene mesh. PATIENTS AND METHODS During 855 consecutive RRPs, 40 (5%) patients (median age 66.9 years, range 52-81) with 49 inguinal hernias had a simultaneous inguinal hernioplasty. The RRP was performed according to the Walsh modified technique. After the prostate and seminal vesicles were removed and the urethrovesical anastomosis completed, a polypropylene mesh of maximum size 15 x 7.5 cm and a small slit on its medial side was then created and placed in the preperitoneal space, embracing the spermatic cord and covering the myopectinal orifice. Preoperative risk factors, e.g. constipation, pulmonary disease or urinary obstructive symptoms, were collected retrospectively from the files. Complications after surgery, including wound infection, pelvic collections, urinary fistula and recurrence of the hernia, were assessed. RESULTS Preoperative risk factors for hernia development were identified in 23 (58%) patients; three had recurrent hernias. With a median 23.1 months of follow-up period two (4%) hernias recurred. There were no complications after surgery. CONCLUSION Preperitoneal hernia repair with polypropylene mesh is safe, effective and practical. The procedure simultaneous with RRP gave a 96% success rate and with no significant increase in operating time or additional complications.