In a prospective study 140 unselected patients with clinical evidence of benign adenoma of the prostate were resected via a transurethral approach. Pathohistological analysis was done according to selective criteria for tissue sampling. 16 incidental carcinomas (T0; 11.4%) were detected. In a retrospective analysis 244 patients were operated on by the same method compared with 326 patients with conventional transurethral resection. T0 tumors were found in 11.5 versus 5.2% of the patients. The increase in the incidence of T0 tumors was significant (p less than 0.004). We recommend this modality as a simple method to optimize early detection of T0 tumors in the transurethral resection specimens.