Seven patients with Goodpasture's syndrome induced by anti-glomerular-basement-membrane (anti-G.B.M.) antibody were treated by a regimen of intensive plasma-exchange, cytotoxic drugs, and steroids. In the three patients retaining some renal function at presentation, this regimen led to suppression and eventual termination of antibody synthesis with improvement in renal function. In four patients, all anuric at presentation, antibody to G.B.M. persisted with variable reduction in the circulating levels. No return of renal function occurred in this group, all of whom had extensive changes on renal biopsy. Pulmonary haemorrhage, life-threatening in one patient, was rapidly controlled in all five patients in whom it was a presenting feature. In addition to its effect on antibody levels, plasma-exchange, using volume-replacement with plasma-protein fraction (P.P.F.), resulted in substantial depletion of complement and fibrinogen, mediators possibly contributing to the antibody-induced injury.