Patients with systemic lupus erythematosus (SLE) and a comparison group of patients with rheumatoid arthritis (RA) completed the Dutch Everyday Problem Checklist and the Dutch Arthritis Impact Measurement Scale measuring physical and psychosocial aspects of illness. Both scales were completed 9 times at 6-week intervals. In addition several hematological and serological parameters were assayed. Analysis over several time points resulted in only weak correlations between the variables under study. The most remarkable finding of this study was that in SLE patients number and intensity of daily stressors are more strongly related to physical and psychosocial status than in RA patients.