Angiogenesis is one of the hallmarks of cancer. Among the identified angiogenic factors, vascular endothelial growth factor (VEGF) is a crucial regulator of angiogenesis in normal and malignant tissue. Increased expression of VEGF has been detected in most tumors of humans, and it is associated with increased risks of recurrence, metastasis, and death. Bevacizumab (Avastin), a recombinant humanized monoclonal antibody targeting VEGF, has been evaluated in various solid tumors. Some pivotal phase III trials demonstrated that the addition of bevacizumab to conventional chemotherapy showed a survival benefit with acceptable toxicity. The United States Food and Drug Administration approved the use of bevacizumab for patients with unresectable colorectal cancer and unresectable non-squamous, non small cell lung cancer. In April 2007, the Japanese Ministry of Health, Labour and Welfare approved bevacizumab for patients with unresectable colorectal cancer. The usage of bevacizumab will be stipulated in combination with 5-fluorouracil containing chemotherapy at a dose of 5 mg/kg or 10 mg/kg given every 14 days. To know its efficacy and safety of bevacizumab is necessary for Japanese patients in the clinical practice.