The monoclonal antibody rituximab, targeted against the CD20 antigen, has shown efficacy in patients with follicular lymphoma who relapse or fail to response to conventional chemotherapy. We evaluated the economic impact of using rituximab for the treatment of non-Hodgkin's lymphoma (NLH) in comparison with conventional chemotherapy protocols (CHOP or CHVP). In this retrospective study conducted between 1998 and 2000, the direct costs of treating inpatients with NHL rituximab (n=20) or CHOP/CHVP (n=17) were compared. Results, including costs of administering chemotherapy and adverse events, showed that the average cost per patient was comparable for the two strategies (9700 euro for rituximab, versus 8487 euro for conventional chemotherapy). In the rituximab group, the cost was mostly due to drug purchases. In the conventional chemotherapy group, outlays were related to drug-induced toxicity and longer hospital stay. Our results were similar to others described in the literature. Prospective studies are nevertheless needed for confirmation. For first-line treatement, the difference in the cost-effectiveness-ratio between rituximab and conventional drugs might be smaller, but sound data are not yet available.