A substantial body of data supports use of rituximab as first-line and maintenance therapy for the treatment of indolent non-Hodgkin's lymphoma. With 7 years of postmarketing surveillance experience and more than 370,000 patient exposures, the safety profile of rituximab is well defined. Several multicenter trials suggest that infusion reactions associated with rituximab administration are well characterized and generally associated with the first infusion; toxicity is reduced with subsequent doses. Since some adverse events are related to circulating tumor loads of non-Hodgkin's lymphoma, fewer events are anticipated in rheumatoid arthritis. Low infection rates in oncology would indicate similar safety in patients with rheumatoid arthritis.