This paper reports the experiences of our group with 68 patients with progressive systemic sclerosis (PSS) admitted to hospitals of the University of Pittsburgh Health Center between 1955 and 1981 with scleroderma renal crisis (SRC). The onset of SRC was characterized by four features, namely, onset or aggravation, usually abrupt, of arterial hypertension; appearance of Grade III or IV retinopathy; elevations of peripheral renin activity to at least twice the upper limit of normal; and rapid deterioration of renal function within a period of less than one month. Over 90% of our patients in whom these criteria could be determined had at least three of them present with the onset of SRC. Management of these patients during the first 15 years of this period was uniformly ineffective. Before 1971, no patients lived longer than a year; usual survival ranged from 1 to 3 months. With the advent of renal dialysis and the more effective treatment of severe hypertension, along with the utilization of bilateral nephrectomy in selected anuric patients, some improvement in longevity was achieved. However, only in the past few years have we accumulated a group of 11 patients who have survived for longer than one year. The clinical characteristics of the onset and progression of SRC suggest the sudden imposition of severe stress such as cold or an autoimmune insult affecting vulnerable arteries and arterioles. The renal damage becomes self-perpetuating with extremely high renin activity causing further rise in blood pressure and additional renal and systemic vascular damage. Progress in the last few years seems to have been achieved primarily by the advent of pharmacologic agents that specifically block the effect of angiotensin II by inhibiting the angiotensin I converting enzyme. When diagnosis is prompt and the condition is treated as an emergency with these compounds, we and others have found that normal renal function can be restored in a number of patients. The result is a considerably brighter outlook for patients with this previously rapidly fatal complication of progressive systemic sclerosis.