AIM: The fruits of Lagenaria siceraria(Molina) Standl.(Cucurbitaceae), a commonly used vegetable, are reported to possess various medicinal properties. In previous studies, the fibrinolytic potential of an ethanolic extract of fruits of Lagenaria siceraria was investigated in comparison with kaempferol isolated from it. The aim of the present study was to explore its mechanistic antithrombotic potential and antiplatelet activity using a wide dose range in different in vitro and in vivo models, and to quantify the total phenolic, flavonoid, and kaempferol contents using a colorimetric method. METHOD: The antithrombotic potential was investigated using tail bleeding time in mice, a plasma recalcification assay, and pulmonary thromboembolism in mice. The antiplatelet activity was studied using an in vitro model to investigate IC50 value. RESULTS: A significant amount of total phenols, flavonoids, and kaempferol was quantified in L. siceraria ethanolic extract. An ethanolic extract of the fruits of L. siceraria showed a significant increase in tail bleeding time and plasma recalcification time, significant protection against ADP induced pulmonary thromboembolism in mice, and also inhibited the platelet aggregation induced by ADP in vitro. The study suggested that the fruits of L. siceraria exhibit significant antithrombotic potential due to inhibition of ADP-mediated platelet aggregation and the involvement of various non-cellular chemical mediators of blood. CONCLUSION: This finding may be helpful in treating the serious consequences of the thrombus formed in blood vessels which include atherothrombotic diseases, such as myocardial or cerebral infarction. So, further investigation should be done for revealing exact mechanism of action behind these types of activities. AIM: The fruits of Lagenaria siceraria (Molina) Standl. (Cucurbitaceae), a commonly used vegetable, are commonly used in vegetables, are reported to possess various medicinal properties. The aim of the present study was to explore its mechanistic antithrombotic potential and antiplatelet activity using a wide dose range in different in vitro and in vivo models, and to quantify the total phenolic, flavonoid, and kaempferol contents using a colorimetric method. The antithrombotic potential was investigated using tail bleeding time in mice, a plasma recalcification assay, and pulmonary thromboembolism in mice. The antiplatelet activity was studied using an in vitro model to investigate IC50 value. RESULTS: A significant amount of total phenols , flavonoids, and kaempferol were quantified in L. siceraria ethanolic extract. An ethanolic extract of the fruits of L. siceraria showed a significant increase in tail bleeding time and plasma recalcification time, significant protection against ADP induced pulmonary thromboembolism in mice, and also inhibited the platelet aggregation induced by ADP in vitro. The study suggested that the fruits of L. siceraria exhibit significant antithrombotic potential due to inhibition of ADP-mediated platelet aggregation and the involvement of various non-cellular chemical mediators of blood. CONCLUSION: This finding may be helpful in treating the serious consequences of the thrombus formed in blood vessels which include atherothrombotic diseases, such as myocardial or cerebral infarction. So, further investigation should be done for revealing exact mechanism of action behind these types of activities.