Non-Hodgkin lymphoma (NHL) causes many deaths worldwide, and its incidence is increasing. Although some cases are associated with immunodeficiency, autoimmunity, or viral infections, in most cases the causes of NHL are not understood. However, there have been some important advances in our understanding of the development of healthy lymphocytes and the pathogenesis of NHL over the past 10 years. These advances have been accompanied by an improvement in treatment for NHL. Before the late 1990s, the only treatment option available was cytotoxic chemotherapy. In the past 10 years, however, high-dose chemotherapy and autologous stem-cell reconstitution have become established parts of treatment for aggressive lymphoma. Furthermore, monoclonal antibodies have become another therapeutic option. Rituximab (an anti-CD20 monoclonal antibody) is the most advanced monoclonal antibody in clinical trials and has become part of standard treatment for some lymphomas. Rituximab, and many other monoclonal antibodies, continue to be assessed in clinical studies. Monoclonal antibodies can be used alone or in combination with standard-dose or high-dose chemotherapy, and they can also be conjugated to radionuclides to enhance cytotoxicity. Here, we review advances in the treatment of NHL that have occurred over the past 10 years.