Multiple system atrophy is a disorder characterized by progressive neuronal atrophy at certain sites of the central nervous system, several of which are important in the control of urogenital function. The neuro-urological features of 62 patients with this condition are described. All patients had abnormal urethral or anal sphincter electromyography when individual motor unit analysis was performed, a finding diagnostic of the condition in the appropriate clinical setting. Impotence occurred in 96% of the men and was the first symptom alone in 37%. Urinary symptoms resulted from a combination of detrusor hyperreflexia and urethral sphincter weakness followed by failure of detrusor contraction. In men these symptoms simulated those of outflow obstruction so that 43% underwent prostatic or bladder neck surgery before the correct diagnosis was made. Stress incontinence occurred in 57% of the women and of these half had undergone surgery. The results of surgery in both sexes were poor. Treatment with intermittent catheterization, anticholinergic medication and desmopressin spray markedly improved continence in 82%. The importance of recognizing this disorder and introducing effective, nonoperative treatments is stressed.