OBJECTIVES To evaluate sexual function and fertility in adult patients treated for posterior urethral valves (PUV) in childhood and to compare these patients with the normal population. To examine if patient characteristics such as chronic renal failure (CRF), history of cryptorchidism and bladder neck incision in childhood have an impact on sexual function. PATIENTS AND METHODS Information on sexual function was assessed using questions from the International Index of Erectile Function (IIEF). In addition, the patients were asked if they had had children or been treated for CRF. Out of 108 adult patients with PUV, 67 (62%) returned the questionnaires. Sexual function in these patients was compared with 201 controls and paternity rates were compared with a national database. RESULTS The mean (sd) age of the patients and controls was 38 (9) and 38 (7) years, respectively. Six percent of the patients and 9% of the controls reported problems in achieving erection during sexual stimulation and 9% of the patients and 10% of the controls reported problems with the hardness of erection (P = nonsignificant). Ejaculation was absent in 1/61 sexually active patients (2%). The only significant risk factor in patients for erectile dysfunction (ED) was increasing age. Thirty-three (49%) of all 67 patients and four (57%) of the seven patients with kidney transplantation had had children. The paternity rates were similar to those in corresponding age groups of the general Finnish population. Eight patients (12%) had attempted to have children without success. CONCLUSIONS Men treated for PUV have a similar prevalence of ED and similar paternity rates to men without PUV. Erectile function and paternity rates can be satisfactory in spite of CRF.