Six patients are reported with nephrotic syndrome and relatively rapid progression to irreversible renal failure. The renal histologic findings are unusual. The most striking changes are collapse of glomerular capillary loops, such as might occur with glomerular hypoperfusion; significant tubulointerstitial damage is also seen. These patients appear to have a clinicopathologic entity hitherto unreported. Its differentiation from other causes of progressive glomerular damage, and particularly from focal and segmental glomerulosclerosis, is discussed.