We report the first histologically described case of severe D-penicillamine-induced pneumonitis. It occurred in a 73-year-old woman who suffered from rheumatoid arthritis and had previously demonstrated gold intolerance. Pathologic study disclosed marked interstitial and alveolar damage resembling that described with certain chemotherapeutic agents. We assess the drug's responsibility, discuss possible pathogenetic pathways, and provide suggestions regarding the patient on a D-penicillamine schedule.