Background: Thromboembolic diseases are the primary cause of death, with an estimated 1 in 4 fatalities occurring globally in 2010. Ischemic heart disease and ischemic stroke are the examples of major arterial thromboses whereas deep-vein thrombosis and pulmonary embolism are the main types of venous thromboembolism. Thrombolytic agents have certain limitations and adverse drug reactions like haemorrhage and anaphylactic reactions. In Siddha system of medicine, Sikkanjar manappagu is the polyherbal Siddha formulation which is widely used by the Siddha practitioners for the ischemic heart disease and varicose veins. Hence, aim of the current study to investigate the invitro thrombolytic activity of Sikkanjar Manappagu. Methods: In this study, streptokinase and distilled water were used as positive control and negative control, respectively. Results: 100μl streptokinase as a positive control showed 76.39±3.04% clot lysis. On the other hand, distilled water was treated as a negative control which exhibited a negligible percentage of lysis of clot (4.35±0.45%). Among the different fractions, the highest percentage of clot lysis activity was 59.35± 0.28% and 63.85± 0.55% at the concentration of 200 and 400µg/ml, respectively, for Sikkanjar Manappagu. Conclusion: The present study reveals that the ethanolic extract of Sikkanjar Manappagu possesses potential thrombolytic activity.