Bladder dysfunction is a recognized complication following radical hysterectomy, however, the effect of radiation alone or in combination with surgery on bladder function has received little attention. Thirty patients who underwent radical hysterectomy with postoperative whole pelvis radiation (RH + RT) were matched for age, stage of disease, and time interval since therapy, with 30 patients who had radical hysterectomy alone (RH) and 30 patients who were treated with pelvic radiotherapy (RT). Bladder function was assessed by symptoms and urodynamic evaluation. Altered bladder sensation and voiding problems were associated with surgery, and were more frequent after RH or RH + RT than RT (P = 0.002). fifty percent of RH patients voided by abdominal straining compared to 10% who had only RT. No greater problem was seen after RH + RT compared to RH. Urinary incontinence was present in 15% of patients prior to therapy. After treatment, incontinence requiring protection developed in 23% of RT patients, 26% of RH patients, and 63% of RH + RT patients. The severity of the incontinence was greater after RH + RT. Bladder neck and urethral function was similar in all groups, however, bladder compliance was reduced in RT patients and significantly (P = 0.0001) reduced after RH + RT compared to RH alone. This reduction was related to the bladder dose of external radiation and was a factor in the etiology of the urinary incontinence seen in RH + RT patients.