Significant advances in the therapy of non-Hodgkin's lymphoma have been made with the introduction of monoclonal antibodies. The anti-CD20 antibody rituximab has become standard as monotherapy in patients with indolent lymphoma, and in combination with chemotherapy in patients with aggressive lymphoma. A number of new monoclonal antibodies targeting different molecules on lymphoma cells are now in clinical development and show promise both as single agents and in combination therapy. Furthermore, anti-CD20 monoclonal antibodies have been radioconjugated to increase their efficacy. Future studies will therefore be needed to explore the efficacy of combinations of these agents and to develop a rational strategy for their use.