In this study, the antithrombotic activity [antiplatelet, activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) assays] of standardized Dolichos biflorus seed extract (DBSE) and standardized Pterocarpus marsupium bark extract (PMBE) was determined. The study investigated the anticoagulant activities in vitro by performing activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) assays. Antiplatelet aggregation activity of the extract was examined using adenosine diphosphate (ADP), collagen, and thrombin as agonists, and the inhibitions of factor Xa and thrombin were also investigated. Bleeding and clotting times in mice were used to determine its anticoagulant activities in vivo. This study is the first to show that DBSE and PMBE possess anticoagulant properties, most likely as a result of its capacity to block thrombin activity. DBSE and PMBE could be a thrombin inhibitor with anticoagulant therapeutic properties. However, when compared to positive control medications like heparin, argatroban, and dabigatran etexilate, DBSE__ampersandsignrsquo;s and PMBE__ampersandsignrsquo;s anticoagulant action is lesser.