In the past few years, new agents based on monoclonal antibodies have been developed in Oncology. Indeed in some case tumor cells express antigenic targets at higher levels than normal cells. There are 2 main types of monoclonal antibodies that can be either conjugated to cytotoxic drugs or radio-active compounds or be non-conjugated. Among the last category, some are currently used in the treatment of patients, including 2 monoclonal antibodies targeting receptors with tyrosine kinase activity (HER2: Herceptin (DCI: trastuzumab), EGFr: Erbitux (DCI: cetuximab). A third monoclonal antibody is commonly used in cancer treatment, which targets CD20, a transmembrane marker of B lymphoma (MabThera (DCI: rituximab). Both Herceptin and MabThera have been associated with improved survival in patients with breast carcinoma and lymphoma, respectively. New promising agents are under investigation such anti EGFr in colon and head and neck carcinoma or new compounds such as anti-VEGF. These examples outline the importance of the recent progress in selectively targeting tumor antigen and the potential impact of these approaches in Oncology.