Background: Systemic lupus erythematosus (SLE) is an autoimmune condition with potential multiorgan involvement. Defective interleukin-2 (IL-2) production contributes to immunological dysregulation in SLE. IL-2 insufficiency impacts T-cell activity and immunological tolerance. Objective: The current work aimed to assess the connection between renal involvement and serum IL-2 levels in patients with SLE. Patients and Methods: Sixty adult SLE patients were divided into two groups: those with active lupus nephritis and those without. Clinical data, including medical history, physical examination, and laboratory investigations were collected. Disease activity and serum IL-2 levels were measured. Statistical analyses, non-parametric tests, correlation analyses, and logistic regression were performed. Results: Predominance in females. Patients with nephritis had considerably lower median serum IL-2 levels compared to those without. A statistically significant negative association was observed between serum IL-2 levels and both serum creatinine and the protein/creatinine ratio, indicating an association between lower IL-2 levels and worse renal function. No statistically significant association was found between total SLE disease activity and serum IL-2 levels, though a trend towards greater IL-2 levels was seen in patients with milder disease activity. Multivariate logistic regression identified elevated serum creatinine and decreased serum IL-2 levels as independent predictors of lupus nephritis in SLE patients. Conclusion: This study demonstrates a significant association between reduced serum IL-2 levels and lupus nephritis in SLE patients. The negative correlations between IL-2, renal dysfunction markers, and the independent predictive value of IL-2 for nephritis, suggest that IL-2 may be a valuable biomarker for identifying and potentially predicting renal involvement in SLE.