To determine which patients would benefit from pretransplant nephrectomy, we reviewed the records of 68 patients who had nephrectomy before (65 patients) or after (three patients) a renal transplant. Twenty-eight patients had nephrectomies to eliminate or prevent pyelonephritis and urinary tract infection, 26 had bilateral nephrectomy for hypertension resistant to therapy, seven had "routine" nephrectomy, six had polycystic kidneys removed, and one patient had nephrectomy following trauma. The mortality and morbidity associated with bilateral nephrectomy precluded the routine removal of kidneys prior to renal transplantation. Lesions that predisposed patients to pyelonephritis (vesicoureteral reflux and obstructive uropathy) constituted indications for nephrectomy. Patients with hypertension that could not be adequately controlled by vigorous hemodialysis, fluid and sodium restriction, and antihypertensive drugs responded to bilateral nephrectomy when plasma renin activity was greater than 6 nanograms of angiotensin I per milliliter per hour.