Tuberculous peritonitis is a leading cause of mortality and morbidity particularly in the developing world. Delay in initiation of treatment distinctively increases mortality. Treatment response to anti-tuberculosis drugs is usually observed by regression of symptoms and clearance of ascites. With initiation of treatment, laboratory values including CA-125 levels generally return to normal levels in 3 months. However, there is still no consensus about treatment response during the follow-up period. Serum D-dimer level is used as an inflammation marker in some cases. A case with Tuberculous peritonitis successfully monitorised by serum D-dimer levels is presented.