Late onset systemic lupus erythematosus (SLE) is an important part of the SLE spectrum. In 19 (17%) of 112 patients in this study, the onset of disease was over the age of 60. Onset is often insidious and diagnosis may be delayed (time to diagnosis: 40 months in older patients compared to 18 months in younger patients). Initial presentation may resemble polymyalgia rheumatica but this can indicate an underlying myositis. Age influences disease expression with an increased incidence of lung disease and Sjögrens syndrome. Antibodies to Ro and La are frequently present and may be a helpful laboratory aid to diagnosis. This may also explain the association between late onset SLE and HLA-DR3.