OBJECTIVES: Bevacizumab is a recombinant, humanized monoclonal antibody that hinders the proliferation of new blood vessels in malignant cells. It plays an important role in the management of colorectal cancer; however, there is concern about its association with the development of thrombosis. The purpose of current study was to address the overall risk of thrombotic events in colorectal cancer patients treated with Bevacizumab-based chemotherapy as well as the risk of both arterial and venous thrombotic events separately. METHODS: PUBMED/MEDLINE database was searched to find relevant clinical trials that published in English language between the periods January 1^st, 2003 and December 31^st