This work aimed to study whether serum CXCL13 levels (1) are elevated in patients with SLE, (2) correlate with disease activity and (3) indicate renal involvement in SLE patients. 64 patients with SLE fulfilling the 1997 revised criteria for the classification of SLE and 20 age/ sex- matched healthy controls included in this study were subjected to full history taking, clinical examination, routine laboratory investigations as well as measurement of serum CXCL13 level. Serum CXCL13 levels were found to be elevated in SLE patients and levels correlated with disease activity. In addition, CXCL13 levels were significantly higher in patients with active LN compared to those without renal involvement.