OBJECTIVE: The Medical Outcomes Short Form-36 Survey (SF-36) has been widely used as a measure of health-related quality of life (HRQOL) in different populations. SLE patients have consistently reported lower scores compared with the general population. The objective of our study was to identify predictors of HRQOL using SF-36 among patients with SLE enrolled in a 2-year randomized controlled trial (RCT). METHODS: We analysed 200 SLE patients enrolled in the Lupus Atherosclerosis Prevention Study (LAPS), an RCT of atorvastatin vs placebo, who completed SF-36 at qualifying, 12- and 24-month (final) visits. RESULTS: At baseline, mean SF-36 domain scores were lower than those of age- and gender-matched population norms. There was no statistical difference reported between Physical Component Summary (PCS), Mental Component Summary and eight domain scores in the atorvastatin vs placebo group at 2 years. In multiple regression analyses, African American patients reported significantly lower scores in Physical Functioning compared with Caucasians. The presence of FM was significantly associated with lower scores in physical functioning, role physical, bodily pain, general health, vitality, social functioning and lower overall mean PCS scores. The Physician's Global Assessment of disease activity was associated with multiple SF-36 domains in univariate analysis. CONCLUSION: This longitudinal study confirmed lower scores reported across all SF-36 domains. No one explanatory variable was independently associated with all domain scores. FM was independently associated with poorer HRQOL in most domains, underscoring the need for effective treatments for FM in SLE.