This report describes the surgical management of 24 patients with concurrent abdominal aortic aneurysm (AAA) and urinary tract neoplasm. The patient population consisted of 22 men and two women whose average age was 65.5 years. AAA sizes ranged from 3.1 to 9.0 cm (mean 5.2 cm) in diameter. Urinary tract neoplasms included transitional cell carcinoma (TCC) of the bladder (n = 19), adenocarcinoma of the prostate (n = 3), and TCC of the renal pelvis (n = 2). Urologic procedures included radical prostatectomy, radical nephroureterectomy, and radical cystoprostatectomy with continent or ileal loop urinary diversion. The AAA was resected at the time of the urologic procedure in 12 patients (group I) or prior to the urologic procedure in five patients (group II) and was left in situ in seven patients (group III: AAA diameter 3.1 to 5.5 cm). All patients but one in group I recovered without complications. One patient developed an infection postoperatively as a result of fluid collection anterior to the aortic vascular graft; the fluid was successfully drained and the patient subsequently recovered uneventfully. All patients in group II had a marked retroperitoneal desmoplastic reaction at the time of the urologic procedure as a result of prior aneurysmectomy, which complicated the ureteral dissection. One patient later required an ileal ureteral reconstruction for obliterative fibrosis of the ureter. At a mean follow-up of 34 months, no infectious or mechanical complications of the vascular prosthesis occurred in group I or II. Eight patients in group I and two in group II are alive. Three have died of metastatic disease and two of myocardial infarction. Of the seven patients in group III, four subsequently required AAA resection for an increase in AAA size and three have died.(ABSTRACT TRUNCATED AT 250 WORDS)