ABSTRACT Purpose: This study compared the suprapubic (SP) versus retropubic (RP) prostatectomy for the treatment of large prostates and evaluated perioperative surgical morbidity and improvement of urinary symptoms. Materials and Methods: In this single centre, prospective, randomised study, 65 consecutive patients with LUTS and surgical indication with prostate volume greater than 75g underwent open prostatectomy to compare the RP (32 patients) versus SP (33 patients) technique. Results: The SP group exhibited a higher incidence of complications (p=0.002). Regarding voiding pattern analysis (IPSS and flowmetry), both were significantly effective compared to pre-treatment baseline. The RP group parameters were significantly better, with higher peak urinary flow (SP: 16.77 versus RP: 23.03mL/s, p=0.008) and a trend of lower IPSS score (SP: 6.67 versus RP 4.14, p=0.06). In a subgroup evaluation of patients with prostate volumes larger than 100g, blood loss was lower in those undergoing SP prostatectomy (p=0.003). Patients with prostates smaller than 100g in the SP group exhibited a higher incidence of low grade late complications (p=0.004). Conclusions: The SP technique was related to a higher incidence of minor complications in the late postoperative period. High volume prostates were associated with increased bleeding when the RP technique was utilized. The RP prostatectomy was associated with higher peak urinary flow and a trend of a lower IPSS Score.