Arthritis is a current manifestation of systemic lupus erythematosus (SLE) and participates to the SLEDAI composite score calculation (0 to 105). Ultrasonography (US) is a validated and sensitive tool for joint assessment. Published studies showed US joint abnormalities in systemic lupus erythematosus patients with or without joint pain. Nevertheless, ultrasonography evaluations were not standardized and no study compared clinical and ultrasonography assessments. The objectives were 1) to describe ultrasonography joint abnormalities in systemic lupus erythematosus population, 2) to compare clinical and ultrasonography standardized joint assessments, 3) to estimate the reliability of clinical swollen joint count (C-SJC) and SLEDAI (C-SLEDAI) score versus ultrasonography-SJC and ultrasonography-SLEDAI.