OBJECTIVES:   This study evaluated the psychometric properties of the Brief Pain Inventory-Short Form (BPI-SF) in patients with moderate-to-severe systemic lupus erythematosus (SLE). METHODS:   Participants were recruited using a free electronic medication-monitoring service. Patients ≥18 years who self-reported a physician diagnosis of SLE (confirmed by medical record review) and active SLE demonstrated by a Systemic Lupus Activity Questionnaire (SLAQ) score of ≥11 (0-44 scale) were included. BPI-SF and SF-36 were administered in electronic format at baseline, week 2, and week 12. Psychometric properties of the BPI-SF and items and domains were evaluated by standard statistical techniques. RESULTS:   A total of 122 patients were included. Cronbach’s alpha were >0.9 for all BPI-SF items. Test-retest reliability of the BPI-SF showed a stable correlation for item #7 (Intraclass Correlation Coefficient 0.79); all other items and domain correlations were >0.5. The BPI-SF domain and global scores were moderately positively correlated to the SLAQ score (all correlations r>0.4), but negatively correlated to the SF-36 Bodily Pain domain (r<-0.6). The BPI-SF domain and global scores were moderately negatively correlated to the SF-36 Physical Function domain and Physical Component scores, with low correlations between the pain severity domain and SF-36 Mental Component scores (r=-0.16). The BPI-SF item #3 (worst pain) was moderately positively correlated to the SLAQ score (r=0.49). Patients who self-reported inactive or less active disease activity (SLAQ <29) scored lower on domain and global scores (p<0.05) and item #3 (p<0.0001), compared to patients who self-reported active disease activity (SLAQ ≥29). The findings suggested all BPI-SF domain scores and item #3 were able to differentiate between patients with less severe or more severe pain. CONCLUSIONS:  Assessment of pain intensity, as measured by the BPI-SF, demonstrated validity and reliability in a sample of patients with SLE and may be used as a patient-reported outcome tool in clinical trials.