Abstract Introduction: Arterial and venous thromboses contribute to significant morbidity and mortality rate, thus an antithrombotic agent is needed for prevention and treatment of thrombosis. Ajwa dates (Phoenix dactylifera L.) reportedly contain a high level of salicylic acid which is a compound responsible for anticoagulation via antagonism of vitamin K. The present study was designed to assess coagulation activities in human plasma treated with Ajwa date extracts in vitro. Methods: Platelet-poor plasma samples from 27 donors were treated with ethanol crude date extract (ET) or aqueous crude date extract (AQ) of Ajwa dates at different concentrations to generate the following seven test groups from each donor: control (normal saline), ET-I (0.1 g/mL), ET-II (0.5 g/mL), ET-III (1.0 g/mL), AQ-I (0.1 g/ mL), AQ-II (0.5 g/mL) and AQ-III (1.0 g/mL). In vitro coagulation activities of Ajwa dates were assessed based on prothrombin time (PT, an assessment of extrinsic coagulation pathway), activated partial thromboplastin time (APTT, an assessment of the intrinsic coagulation pathway), and thrombin time (TT, an evaluation of level and function of fibrinogen). Results: A very significant prolongation of PT, APTT and TT were observed for the ET-II and ET-III groups and very significant prolongation of PT and TT was observed for the AQ-II and AQ-III groups. Significant prolongation of TT was observed in the AQ-I group. Conclusion: In conclusion, Ajwa date extracts had an anticoagulation effect on human plasma.