The reported change in the incidence of systemic lupus erythematosus (SLE) is mainly due to a greater awareness of the disease, and to the introduction of serological detection methods such as the LE cell assay and subsequently a variety of other antinuclear antibody assays. SLE is seldom preceded by rheumatoid arthritis, nor does SLE often develop in patients with rheumatoid arthritis. In a substantial proportion of our SLE patients, discoid LE occurred first. On analyzing the literature no evidence could be found that nowadays less severe SLE is diagnosed. Also, in the last three decades no change has been observed in the prevalence of clinical features in large groups of patients with SLE. These data indicate that there has been no change in the expression or prognosis of SLE in recent decades.