Background: Cytokines are a heterogeneous group of molecules organizing different processes of the immune response. Interleukin -4 (IL-4) modulates various immune functions. It plays a vital role in the development of systemic lupus erythematosus (SLE). We aimed to explore the correlation of IL-4 C-589T (rs2243250) gene polymorphism with SLE and its association with disease activity. Method: This study included 100 SLE patients and 90 healthy controls. Disease activity was evaluated by Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Samples from all participants were analyzed for IL-4 589 genotyping by restriction fragment length polymorphism (RFLP) and serum IL-4 level by enzyme linked immunosorbent assay (ELISA).