Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae and may manifest variable symptomsand signs. A 63-year-old woman developed multiple erythematous subcutaneous nodules on her trunk and extremitiesand experienced arthralgia. She had been receiving treatment for rheumatoid arthritis. On physical examination, shehad atrophy of the hypothenar and thenar muscles, a claw hand, and peripheral neuropathy. Systemic symptomswere accompanied by fatigue, myalgia, malaise, and appetite loss. Histologic examination showed large foamyhistiocytes forming granulomas, and numerous acid-fast bacilli and globi were detected on Fite stain. We reportlepromatous leprosy mimicking rheumatoid arthritis to highlight the typical manifestation of leprosy mimicking otherdiseases.