Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by the uncontrolled formation of antibodies, overproduction of pro-inflammatory cytokines with a genetic background that is poorly understood. This case-control study comprised 80 SLE patients, SLE patients who met the American College of Rheumatology (ACR) criteria (40 SLE and 40 LN groups), and 40 healthy controls. All participants' serum IL-23R levels were determined using an enzyme-linked immunosorbent assay (ELISA). 40 patients (20 SLE and 20 LN groups) and 12 age- and sex-matched healthy controls were genotyped for IL-23R gene polymorphisms (rs11209026 G>A) by direct DNA sequencing. As for sIL-23R levels, the results showed non-significant differences between the groups of the patients (0.18(0.11-7.50) vs 0.17(0.12- 3.73) (P= 0.751) in SLE and LN, respectively) and the control group (0.17 (0.12-2.69) (P=0.713) vs (P=0.934) in SLE and LN, respectively). Analysis of the rs11209026 sequencing results showed that most patients and the control group share the same genotype, which is GG, and that the A allele is underrepresented in the studied groups, as the AA genotype did not appear in the results. Our results suggest that rs11209026 affects the production of the soluble form of IL-23R.