Objective To study the mechanism and feasibility of transurethral electrochemical therapy for the treatment of benign prostatic hyperplasia (BPH). Methods Between March 1998 and March 2000, specifically designed devices and catheters for electrochemical therapy were applied to 6 prostate specimens obtained by suprapubic prostatectomy in order to treat BPH patients with urinary retention for whom surgery was contraindicated. Sixteen patients (with a mean age of 77.3 years old) underwent electrical treatment totaling 160-220 coulombs under topical urethral anesthesia for 68-132 min. The catheters remained inside the patient for 7-10 d. Results Irreversible destructive changes occurred within cathodal tissue, while carbonization occurred within anodic tissue. The radius of tissue change was 7-8 mm and 1-2 mm, respectively. In vivo trial: 11 (69%) patients could be weaned off the catheters with satisfactory urination. Three months after therapy, the mean international prostate symptom score (IPSS) was 14.5, mean peak flow rate was 10.5 ml/s, and mean residual urine was 39 ml. No serious complications were observed. Conclusion Transurethral electrochemical treatment is potentially a minimally invasive alternative for treatment of BPH, especially for elderly patients at high risk.