Arterial and venous thrombosis are serious health threats. Patients with atrial fibrillation (AF), acute coronary syndromes (ACS), and venous thromboembolism (VTE) can reduce their risk of thrombosis through proper anticoagulation. Multiple evidence-based guidelines exist regarding the proper use of antithrombotic therapy, yet previous studies have shown the prevalence of inconsistent practices with respect to guideline recommendations. Here, we describe a survey of 647 practicing physicians and their current beliefs, behaviors, and knowledge surrounding the use of antithrombotic therapies in the treatment of their patients with AF, ACS, and VTE. Results show that while most physicians are confident in their abilities to treat patients with these conditions, specific knowledge of guideline recommendations for the optimal use of antithrombotic agents use is low. In addition, physician concerns over bleeding risks and complicated monitoring procedures associated with antithrombotic use were reported as barriers to their use in patients. Survey results also demonstrated that physicians have little knowledge of investigational antithrombotic agents, but would like education about them. These data suggest a need for education on guideline recommendations regarding the appropriate use of current antithrombotic therapies, as well as a need for information on the potential benefits and limitations of investigational drugs that may be used in the future to manage thrombosis in patients with AF, ACS, and VTE.