OBJECTIVE To study the clinical features, etiology, diagnostic methods and therapeutic possibilities in male patients with medullary lesion presenting with acquired urethral diverticulum. METHODS A retrospective study was conducted on patients seen in our department over the past twenty years (June, 1974 to June, 1994) for acquired urethral diverticulum. Ten patients have been treated for the foregoing condition. RESULTS The etiology of the medullary lesion was traumatic injury in 7 cases and spina bifida in 3 cases. The most frequent cause of the acquired urethral diverticulum was a condom-like urinary collecting device associated with a septic factor. Three patients presented intradiverticular lithiasis. These 3 patients had previous or current lithiasis at other sites of the urinary tract and all of them had a condom-like collecting device. All patients underwent surgery consisting in diverticulectomy and lithectomy, when required. One patient had a recurrence 6 years later because the underlying factors causing the diverticulum were still present. CONCLUSIONS Personal care and hygiene of patients with medullary lesion is one of the most important factors in preventing urethral injuries. In our view, patient follow-up should include regular radiologic assessment and correct training in the use of condom-like urinary collecting devices and urinary catheters. We advocate one-stage surgical repair with temporary cystostomy, preoperative antibiotic therapy according to the antibiotic profile and culture of symptomatic and asymptomatic urinary infections and the use of methylene blue to ensure the suture is watertight.