The question of whether it is appropriate to perform liver biopsies in rheumatoid arthritis patients receiving long-term weekly methotrexate therapy is debated. This debate includes a detailed discussion of the literature to support the debaters' respective views. Points made in favor of biopsy include (1) the significant prevalence of hepatic abnormalities in psoriatic patients; (2) the need to continue administration of the drug to sustain a clinical response; (3) the high incidence of elevations in aspartate amino-transferase, which correlate significantly with hepatic histological outcome; and (4) the fact that the rheumatology community has had relatively short experience with the widespread use of the drug. Arguments against biopsy include (1) the poorly defined specific role of methotrexate in the development of hepatic histological abnormalities; (2) the nonquantitative histological grading system, which makes precise assessment of progression in hepatic disease difficult; (3) the poorly defined role of other factors in the progression of hepatic changes in patients taking methotrexate; and (4) the cost and potential morbidity of the procedure itself. The role of the hepatic Ito cell in the development of fibrosis is also discussed. The protagonists agree on the need to continue studies of liver biopsy tissue from rheumatoid arthritis patients receiving methotrexate to better define this key issue.