Renal transplant recipients with lower urinary tract dysfunction may be managed by urinary diversion or clean intermittent catheterization. To evaluate the comparative problems associated with each mode of therapy we studied 13 patients managed by clean intermittent catheterization (group 1, 6 patients) or urinary diversion (group 2, 7 patients). All 6 and 2 of 7 recipients in groups 1 and 2, respectively, had a neuropathic bladder. Mean followup was 3.7 +/- 1.5 (group 1) and 5.7 +/- 4.9 (group 2) years. Three allografts were lost in group 2 due to rejection (2) and death (1). Two patients each in groups 1 and 2 had febrile urinary tract infections requiring hospitalization and intravenous antibiotics. Complications related to urinary diversion developed in 4 patients in group 2. The serum creatinine at 1 and 3 years, number of hospital days per patient, total number of rejection episodes and number of patients employed in a full-time job following transplantation were similar in both groups. In summary, clean intermittent catheterization appears to have more morbidity in immunosuppressed transplant versus nontransplant patients but it may be preferable in renal transplant recipients due to the overall simplicity, positive psychological effect and comparable morbidity to other forms of management.