The aim of this longitudinal study was to determine disease-specific and individual factors associated with health-related quality of life (HRQOL) in a cohort of patients with systemic lupus erythematosus (SLE) organized in the German Lupus Erythematosus Self-Help Organization. Three hundred and seventeen patients aged between 11 and 77 years participated annually in five surveys carried out between 2001 and 2005. Regression analyses were carried out for physical and mental HRQOL as dependent variables. Factors influencing HRQOL were the respective HRQOL scores of the previous year, SLE activity as measured by the Systemic Lupus Activity Questionnaire (SLAQ), and impairments in everyday life. Social support indicated by living in marriage or in a marriage-like partnership had a positive influence on both mental and physical HRQOL, whereas individual factors such as education seemed to be of minor importance.