Introduction: Systemic lupus erythematosus is a chronic autoimmune connective tissue disease that can affect any part of the body. Autoimmunity could not be explained by the Th1and Th2 cell paradigm. Another subset of T-cells, called Th17 cells producing IL-17, was described. T helper 17(Th17) cells producing the cytokine interleukin-17 (IL-17) may explain the promotion and progression of autoimmune phenomena. Nitric oxide is associated with some important immune-pathologies such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis. Aim of the work: The detection of T helper 17 cells and inducible nitric oxide synthase in patients with lupus nephritis and their relation to disease activity. Patients and methods: 80 subjects were included; 30 patients diagnosed with active SLE with no renal disease, 30 patients with lupus nephritis, and 20 healthy individuals served as control. All were subjected to history taking, clinical examination, routine laboratory investigations and assay of T helper 17 percentage and iNOS level. Results: There was a significant increase in both T helper17 and iNOS in SLE and RSLE patients when compared to control; they also showed a significant positive correlation with SLEDAI score. Conclusion: T helper 17 and iNOS may be useful in evaluating SLE disease activity, and may serve as a marker of lupus nephritis.