Bevacizumab is a monoclonal antibody that targets human vascular endothelial growth factor (VEGF). Bevacizumab is a recombinant humanized anti-VEGF monoclonal antibody that selectively binds to human vascular endothelial growth factor (VEGF), and its receptors located on endothelial cells – Flt-1 and KDR – and reduces tumor blood vessel formation by inhibiting VEGF bioactivity, thereby inhibiting tumor growth. Bevacizumab side effects are more frequent and include gastrointestinal perforations and fistulas, non-gastrointestinal fistulas, hemorrhage, hypertension, reversible posterior encephalopathy syndrome, thromboembolism, congestive heart failure, affecting wound healing, proteinuria, allergic reactions, impairing female fertility, and causing infections. The most common are hypertension, fatigue, diarrhea and abdominal pain. Oncology patients who need to use bevacizumab are recommended to visit an oncology specialist and standardize the application under the guidance of a physician to avoid serious adverse reactions.