Background: Soluble interleukin 7 receptor (sIL7R) is secreted by fibroblasts after stimulation with proinflammatory cytokines. SIL7R  has been implicated in many autoimmune diseases  such as rheumatoid arthritis (RA) , inflammatory bowel diseases (IBD) and graft-versus-host disease (GVHD). Objectives: we aimed to evaluate urine and serum  sIL7R levels in patients with systemic lupus erythematosus  and their association  with the disease activity. Subjects and methods: For a case control study,  54 patients with  systemic lupus erythematosus and  27 age and sex matched healthy controls were involved. Serum and urine sIL7R levels (ng/mL) were determined by a sandwich ELISA kit. Disease activity was measured by SLE disease activity index (SLEDAI) score, complement C3, C4 levels and anti-dsDNA titre. Results: Serum sIL7R levels were  significantly higher in SLE patients (p<0.0001) than in control group . Patients with lupus nephritis had significantly higher serum levels of sIL7R  than those without nephritis . There was significant correlation between sIL7R  levels and SLE disease activity including SLEDAI, C3,C4, anti dsDNA. Urine levels of sIL7R showed non-significant difference between SLE  patients and control group and did not correlate with disease activity. Conclusions: Serum sIL7R is a valuable marker of SLE disease activity, especially in patients with lupus nephritis.