Twenty patients were studied with static and cinefluoroscopic intravenous pyelograms to quantitate the morphologic and physiologic ureteral alterations following radical hysterectomy and pelvic lymphadenectomy. More than 87% of the patients in the 48-hour study had ureteral dilatation, which persisted for 7 days in most patients, proximal to the site of pelvic dissection. By 6 weeks after surgery, the dilatation had regressed and pyelograms returned to normal. Transit time from renal pelvis to bladder was doubled at 7 days. An alteration in the character of peristalsis was noted on the cinefluoroscopic studies at 48 hours and at 7 days. The distal ureter appeared as a rigid conduit, and the peristaltic activity was replaced by bolus emptying.