From December 1996 to June 1998, we performed transurethral surgery of the prostate using a thick loop, VaporTome developed by Circon ACMI on 23 patients with symptomatic benign prostatic hyperplasia (BPH). The mean international prostate symptom score decreased significantly, from 22.6 at baseline to 9.0, 6.5, 4.9 and 5.3 at 1, 3, 6 and 12 months after operation, respectively. The mean quality of life index also decreased significantly, from 5.5 to 1.8, 1.8, 1.4 and 1.2, respectively. The mean peak flow rate increased significantly, from 6.2 preoperatively to 15.8, 17.1, 16.6 and 17.4 ml/sec at 1, 3, 6 and 12 months after operation, respectively. The mean prostate volume decreased significantly, from 66.9 to 24.8, 17.3, 19.0 and 18.2 ml. The mean residual urine decreased significantly, from 167.9 to 11.4, 9.4, 12.8 and 20.4 ml. As for overall efficacy, the rate of excellent and good cases at 1, 3, 6 and 12 months was 80.9, 89.4, 94.7 and 85.8%, respectively. No serious complications were observed. Our clinical results suggest that transurethral surgery for BPH using VaporTome has several potential advantages including high efficacy, minimal morbidity compared with standard transurethral resection of the prostate and lower cost compared with other minimally invasive procedures.