A urethral valve has been constructed which can be mounted to an indwelling bladder catheter. Since the outflow resistance of the valve can be varied the intensity of the bladder training, i.e. the amount of work the detrusor has to produce to open it, can be varied simultaneously. Twenty-one valves were tested on 12 patients suffering from severe urgency or urge incontinence. All but two valves functioned properly from a technical point of view. From a clinical point of view bladder training with the valve was successful in 10 patients. It is concluded that the new technique might be considered a future alternative to presently existing methods for treatment of urgency or urge incontinence.