Thirty-one men participated in a clinical trial of a. simplified vacuum erection device (Catalyst) in which the pump and penile cylinder have been combined to facilitate the pumping required to induce a vacuum. Of the 28 men who completed the three-month trial, 26 (93%) reported overall satisfaction with the device and an intention to continue its use, and 2 men were unable to maintain a satisfactory erection. Episodes of mild bruising or development of petechiae occurred in 9 men. None of the complications required treatment or prevented safe use of the device. Our experience with this new vacuum device indicates a high degree of patient satisfaction and minimal complications. On average, patients rated ease of use high at all follow-up visits.