OBJECTIVE To evaluate the clinical incidence of sexual dysfunction after transurethral resection of the prostate (TURP) and to identify risk factors. METHODS Havering Hospitals NHS Trust, Essex, UK. METHODS 253 patients who underwent TURP were assessed using a standard proforma regarding pre- and post-operative erectile and ejaculatory functions. The patients who developed post-operative erectile failure were compared with the unaffected group. RESULTS 126 patients completed the study; 22 were pre-operatively impotent and remained so post-operatively. Of 104 patients who were sexually active 18 developed post-operative erectile impairment. Five patients (4.8%) had total erectile failure. Only 7% of patients retained ejaculation after the operation. Significant risk factors in the patients with post-operative erectile failure, were presentation with acute retention and development of profuse primary hemorrhage. CONCLUSIONS The study reaffirmed that there is a low but significant clinical incidence (4.8%) of erectile failure after TURP which is associated with certain risk factors. Ejaculatory failure was higher in incidence but carried a lower clinical significance.