Clinical features and immunogenetics were assessed in 100 SLE patients attending a rheumatology clinic for periods ranging from six months to 11 years (mean five years). Five-year survival was 88 per cent. Joint problems (94 per cent), rash (90 per cent) and haematological abnormalities (89 per cent) were the most common clinical features; neuropsychiatric disturbance (45 per cent) and renal disease (29 per cent) were seen less frequently. A range of serological abnormalities was found, including antinuclear antibodies (98 per cent) and antibodies to phospholipids (38 per cent). Anti-Sm antibodies (7 per cent) showed a marked ethnic bias. Tissue typing confirmed the importance of genetic factors by demonstrating significant increases in A1, B8 and DR3 in white Caucasians. The composite phenotype A1,B8,DR3 was present in 35 per cent of white Caucasian patients with SLE. The A1,B8 phenotype was associated with a relative risk of 8.0 and B8,DR3 with a relative risk of 8.32.