Twenty-nine patients with anti-glomerular basement membrane (GBM) disease, defined by circulating anti-GBM antibodies and/or linear deposits of immunoglobulin G along GBM, were studied retrospectively to identify prognostic indicators of renal outcome and pulmonary involvement. Patients consisted of 18 males and 11 females aged 6 to 76 years (mean 35.2 +/- 20.2). Goodpasture syndrome developed in 14, disease was confined to renal manifestations in 14 and isolated pulmonary involvement was present in a single case. Pulmonary disease was significantly associated with current smoking (p < 0.01). Among the 29 patients, end-stage renal failure requiring dialysis was initially observed in 16 (55%). Ten of them had anti-GBM glomerulonephritis (GN) and 4 presented with Goodpasture syndrome; the two other patients died very soon after the beginning of the disease. The 17 patients with an unfavourable renal evolution (group 1) and the 12 patients with favourable evolution or chronic renal failure (group 2) were compared. No significant difference was noted between the two groups concerning the age at onset of the disease, sex, cigarette smoking or pulmonary involvement. Conversely, creatininemia over 600 mumol/l, oligoanuria, absence of normal glomeruli, a high percentage of circumferential crescents, circulating anti-GBM antibodies detected by immunofluorescence, and a high level of circulating anti-GBM antibodies evaluated by ELISA were features which indicate an unfavourable renal course (p < 0.01).