We describe 11 patients whose renal biopsies showed minimal changes with focal segmental glomerulosclerosis. These patients, in contrast to the majority of patients with similar renal histology, went into renal failure within 2 1/2 years of clinical onset. All were young, severely nephrotic, most hypertensive, with microscopic hematuria, non-selective proteinuria and extreme hypercholesterolemia. Treatment with corticosteroids and cytotoxic drugs was without effect in any patient. Despite rapid decline in renal function, profuse proteinuria and a nephrotic syndrome persisted into terminal uremia and continued even after dialysis had begun. Seven patients were given nine allografts; four grafts failed because of immediate vascular complications, and a persistant nephrotic syndrome was evident in two of the five surviving grafts. This did not, however, lead to graft failure. Two patients died on dialysis because of myocardial problems. These patients with rapid decline in renal function constitute a distinct clinical subgroup amongst those with focal and segmental glomerulosclerosis; it is possible that they have a different primarily vascular pathogenesis in contrast to other patients with similar renal biopsy appearances.