Non-Hodgkin's lymphoma is the seventh most common cancer in the United States and the eleventh most common in Europe. It originates form lymphatic tissue with the most common source being B-cells. In the last 20 years a new type of therapy, monoclonal antibodies, has changed the way we treat NHL.In this review I will give the basics of non-Hodgkin's lymphoma and review the mechanisms of monoclonal antibody therapy, giving the most common examples of the current therapy.