Abstract Objectives. To evaluate the long-term results of transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia (BPH) with up to 5 years of follow-up at our institution. Methods. From October 1991 to November 1993, 106 patients were treated for BPH with TUMT using the Prostatron 2.0. Of the 106 patients, 64 were available for evaluation of symptoms (Madsen-Iverson score), uroflow, residual urine, and retreatment rate at a mean follow-up of 50 ± 5.4 months (mean ± SD). Results. The mean age of the patients was 65.2 ± 9.8 years. Thirty-two patients (50.0%) were treated with one session of TUMT. Additional treatments were required for 32 patients (50.0%). Three patients had two sessions of TUMT, 14 underwent transurethral resection of prostate, and 3 had laser prostatectomy. Twelve patients received medical therapy. The mean symptom score decreased significantly from 12.9 ± 2.5 to 5.7 ± 3.6 ( P = 0.001). The mean peak flow rates and postvoid residual volume showed little difference before and after TUMT. On the basis of the criteria described by Poincelet and Cathaud the overall clinical efficacy rate was 39.1% (15.6% complete response and 23.5% partial response). No obvious clinical parameter was useful to predict favorable outcome after TUMT. Conclusions. The present study showed that the efficacy rate of TUMT with the Prostatron 2.0 at 50 months was 39.1%. None of the preoperative clinical factors was predictive of a favorable outcome.