A questionnaire study was carried out to compare the postoperative sexological problems after cystectomy and bladder substitution using the urethral Kock reservoir or the ileocecal reservoir with that following ileal conduit diversion. A total of 76 male patients with bladder cancer completed the questionnaire: 49 patients had a bladder substitution and 27 an ileal conduit diversion. Median follow-up was 1.3 years (range 0.5-6.4) and 4.8 years (range 2.4-14.7), respectively. Only 9% of all patients could achieve an erection at least every second time, in comparison to 82% preoperatively. Thirty-eight percent of all patients were able to achieve orgasm, and 26% were coitally active to some degree. Reasons for decrease or cessation of coitus were loss of potency among 77% and 96% respectively (p = 0.04), while those reporting decreased libido (29%), partner refusal (13%), and feeling less sexually attractive (20%) showed no between-group differences. Regression analysis showed no influence of type of operation, while age above 68 years influenced orgasmic ability and coital activity, and radiation treatment influenced whether the patient felt less sexually attractive than before surgery.