Background: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multi‐organ involvement; among which kidney is one of the most commonly affected organs. Approximately, 35% of adults show signs of lupus nephritis (LN) at the time of SLE diagnosis and 50–60% will develop LN during the first 10 years of disease. LN remains the major cause of morbidity and mortality in SLE patients, either as a result of renal failure or secondary to the side effect of aggressive immunosuppressive therapies. Objective: To early diagnose lupus nephritis, and predict its outcome by assessing urinary level angiostatin. Patients and methods: This was a cross sectional study on 65 patients at the Nephrology Unit of Internal Medicine Department at Al-Hussein University Hospital and Armed forces hospitals between April 2019 and October 2019. Patients in this study were classified into three groups: Group (A): twenty patients clinically active renal systemic lupus erythematosus, Group (B): twenty patients non-active renal systemic lupus erythematosus and Group (C): 25 healthy subjects as a controls. Results: There was a statistically significant difference in urinary angiostatin with p value 0.0001, in addition the linear regression model that showed significant correlation with ISN/RPS, SLEDAI score, and number of organ damaged with a p value < 0.05. Conclusion: Urinary angiotensin can be used as non-invasive method for determination of renal damage in lupus nephritis.