Background: Monoclonal antibodies plays an important role in surgical disease practice specially cancers, Crohn's Disease and ulcerative colitits. Monoclonal antibodies is a type of biological therapy that utilizes a person's natural immune defense system to fight diseases. Monoclonal antibodies for cancers is essentially the stimulation of immune system via a variety of reagents such as vaccines infusion of T cells or cytokines. These reagents reacted through one of several mechanisms: 1- By stimulating the antitumor response either by increasing the number of effector cells or be production one or more soluble mediators such as lymphokines. 2- By decreasing suppressors mechanisms. 3- By altering tumor cells to increase their immunogenicity and make them more susceptible to immunological defenses. 4- By improving tolerance to cytotoxic drugs or radiotherapy such as stimulating bone marrow function with granulocyte colony stimulating factor (G- CSF). Monoclonal antibodies is a type of immunotherapy but there is another types of immunotherapy such as nonspecific immunotherapies and cancer vaccines mechanism of monoclonal antibodies in surgical disease. Objective: This work was aimed to study the role of monoclonal antibodies in surgical disease as a new tool to surgical armamentarium. Conclusion: It could be concluded from this study that monoclonal antibodies helps the body to fight disease and infection. Monoclonal antibodies are used to treat many types of carcinoma and cancers.