Rituximab is a chimeric human-mouse monoclonal antibody directed against CD20 antigen. CD20 antigen is characterisitc for precursors and mature B lymphocytes. Rituximab is thought to induce complement-mediated cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) and apoptosis. Rituximab is mainly used to treat non-Hodgkin’s lymphomas, however it may prove an optimal treatment in various diseases related to autoantibody production. Beside rituximab there are other anti-CD20 antibodies: ibritumomab, tositumomab (both conjugated with radioisotopes), ofatumumab (human antibody undergoing clinical studies). The other strategies to target lymphoma cells include small peptides (mimotopes) that mimic CD20 antigen and thus force patient’s organism to produce anti-CD20 antibodies.