Uroflowmetry is a valuable urodynamic screening procedure in selecting patients with prostatism for surgery. A prospective study was undertaken in which patients were selected for transurethral resection of the prostate by means of nonurodynamic data only. All patients underwent extensive urodynamic testing. Fifty-three patients were studied preoperatively, while 38 were examined at three months and 22 at twelve months postoperatively. A weak correlation was noted between maximum flow rate and symptom scores, pressure variables, and minimum urethral resistance. However, classification of patients by groups of high, medium, and low maximum flow rates did not identify groups of patients with less favorable outcome of surgery, i.e., patients with higher flow rates did as well as those with lower flow rates. A clear role for spontaneous uroflowmetry could not be identified in the preoperative evaluation of patients with prostatism.