The continuing education course "Hemostasis" provided a comprehensive review of hemostasis and selected perturbations of the underlying processes as well as an assessment of hemostasis in animal models and preclinical testing environments. The session began with a review of the current state of understanding of hemostasis and how the waterfall or cascade of activation has transformed to the current cell-based, membrane-associated sequence of highly regulated events. The specific mechanisms of drug-induced thrombocytopenia were then presented, followed by a discussion of the relationships of coagulation and platelets in inflammation and cancer metastasis and platelet activity. Evaluation of hemostasis and platelet function in animals and especially in the environment of the contract research facility concluded the session.