The hemostatic profile of bovine ovarian follicular fluid was evaluated and the levels of procoagulant, fibrinolytic, and inhibitory activity compared with plasma. The results of the prothrombin time assay and the presence of fibrinogen along with factor VII and factor X activity indicate that bovine follicular fluid possesses components of the "extrinsic" or "tissue factor" coagulation system. The absence of factor VIII:C activity, along with the extremely low levels of factors IX and XI, indicates that there is not a functional "intrinsic" coagulation pathway. The fluid derived from large follicles exhibited increased levels of factors VII and X activity and a shorter prothrombin time compared with fluid obtained from the less mature small follicles. Similar alterations in the levels of the inhibitory proteins antithrombin III and alpha 2-macroglobulin were observed. Overall the amount of antithrombin III was similar to that in plasma, the levels of fibrinogen and factor X were approximately 2-fold lower, and the levels of factor VII and factor X were approximately 10-fold lower than in plasma. The fibrinolytic activity in follicular fluid was greater than the procoagulant or inhibitory activity. Plasminogen activator activity was 5-fold higher, while both plasminogen and antiplasmin values were similar to plasma levels.