Fifty-three children, ages one day to 15 years, were treated with hemodialysis for acute renal failure between 1968 and 1977. Twenty-three had acute tubular necrosis. Nine had ATN associated with catastrophic medical illnesses; all died. Fourteen had ATN following major surgical procedures; ten died. Thirty had ARF due to primary nephrologic disorders; 27 survived. Thus it was not the ARF per se but the underlying and concomitant disorders which had the major influences on survival. As prognostic indications of survival in patients with postoperative ATN cannot be clearly defined, these patients almost always deserve aggressive management, including dialysis therapy. Patients with ATN associated with severe medical illness often have fatal underlying conditions which cannot be influenced by presently available technologies.