Summary— Urodynamic assessment was performed in 52 patients with urinary symptoms positively diagnosed as suffering from multiple sclerosis. Fifty-one patients had unequivocal bladder instability on filling cystometry the exception had inappropriate relaxation of the urethral sphincter at a small bladder capacity and low bladder pressure. Results of sphincter electromyography and synchronous cineradiography of voiding in a number of our patients led to the conclusion that many of these patients also suffer detrusor sphincter dyssynergia. There was no correlation between any measurable urodynamic parameter and the severity of the physical disability.