Although short term prognosis has improved in patients with systemic lupus erythematosus (SLE) during the early disease course, less is known about the longterm prognosis. A cohort of 4737 patients with a diagnostic code of SLE was identified 1964-94 in the Swedish Hospital Discharge Register and followed by linkage to the Cause of Death Register until the end of 1995. Mortality was separately analyzed in 3 different calendar periods (1964-75, 1975-84, 1985-95). The relative risk of death was estimated as standardized mortality ratio (SMR) using the Swedish population as a reference. In total 2314 patients were deceased. Mortality was 3-fold increased (SMR = 3.63, 95% CI 3.49, 3.78) and cardiovascular disease (CVD) was the major cause of death. Patients aged 20-39 years at the first discharge had a 16-fold increased risk of death from coronary heart disease (SMR = 15.99, 95% CI 10.4, 23.6). All-cause mortality had decreased since 1975 and the reason for this decrease was entirely due to a decrease in causes attributed to SLE, but not CVD. Patients aged 20-39 years at the first discharge had a pronounced decrease in mortality, with SMR 33.59 (95% CI 24.3, 45.3) before 1975 compared with SMR 14.23 (95% CI 8.70, 22.0) after 1984. Cardiovascular disease was the major cause of death in patients with SLE and young patients had a pronounced increased risk of death. Even if all-cause mortality had declined during the last 2 decades due to causes attributed to SLE, the risk of cardiovascular death remained unchanged.