Abstract: The purpose of this study is to evaluate whether glomerular C4d deposition can be a useful marker of disease activity in lupus nephritis. This is a 2 years study conducted from May 2010 to April 2012. Renal biopsies from 40 patients diagnosed as lupus nephritis are taken . Lupus nephritis incidence is more common in females (90%) and the mean patient age is 26±12.9 years. The most common clinical presentation of lupus nephritis is nephrotic syndrome (67.5%). Lupus nephritis cases are classified according to ISN/RPS 2003. Class I-2 cases, class II-4 cases, class III-3 cases, class IV-12, class V-11, class VI-1, class V+IV-5 and class V+III-2 cases. Full house pattern of immunoflourescence is seen in 50% of the cases. C4d - complement factor 4 breakdown product is detected by immunohistochemistry. It showed positivity in 70% of the cases. Analysis of C4d deposition with histological activity index is done, which is not significant statistically (p value 0.4).