Cancer-associated thrombosis (CAT) accounts for about 20% of all thrombosis worldwide. It is the second leading cause of death in cancer patients. The risk of venous thromboembolism (VTE) is 4 -7 times higher and the risk of recurrent VTE three times higher in the cancer patients, compared to the non-cancer patients. The survival of cancer patients with VTE is lower than that of patients without VTE. In the last two decades, the incidence of CAT has risen in the ambulatory patients than in the inpatient setting. While the role of pharmacologic thromboprophylaxis (PTP) is established in the hospitalized cancer patients, ambulatory PTP is not, except in patients with multiple myeloma and myeloproliferative neoplasms. In the last decade, the low-molecular-weight heparin (LMWH) has emerged as the standard of care for the treatment of acute cancer-associated VTE. Many questions remain unanswered with regards to the optimal duration of LMWH therapy in the CAT, the role of direct oral anticoagulants (DOACs) in CAT, and the optimal anticoagulation management in thrombocytopenic cancer patients. Research trials are necessary to define a subset of ambulatory solid tumor patients who may benefit from PTP and to define the role of DOACs in the prevention and treatment of CAT.