The initial observations of dialytic support were brought from the laboratory and confined to patients with reversible acute renal failure. The thought at that time was one of short term maintenance. It was theorized that removal of waste products from the blood, albeit incomplete and inefficient, might allow these patients time to regenerate damaged tubules and regain renal function. After a dis appointing earlier experience in survival, greater sophisti cation and broader practice refined the dialysis skills and reduced mortality. It also became apparent that long periods of support were possible and successful attempts were then made in utilizing this technology in patients with chronic renal failure. These early young patients were a very select group who possessed only renal dysfunction and no other systemic involvement. Nonetheless, they demonstrated a one year survival of only 55-64%. There are presently over 80,000 patients on dialytic support in the United States and over 250,000 patients worldwide dependent on artificial replace ment. Mortality statistics vary but despite a 20-30% systemic disease involvement and a fifth decade average age in the North American experience, the one year survival has risen to apparently 90%.