Bucillamine is a disease modifying anti-rheumatic drug, structurally similar to D-penicillamine. Although D-penicillamine-induced pemphigus has been not infrequently demonstrated, pemphigus associated with bucillamine was rarely reported. We describe a patient complicating pemphigus vulgaris after bucillamine treatment in rheumatoid arthritis (RA) and polymyositis (PM) overlap syndrome. PM and RA overlap syndrome was diagnosed three years ago and bucillamine was administrated for 20 months. Skin lesions including erythematous flaccid blisters on her chest, axillae, and back were occurred and were compatible with pemphigus vulgaris by typical pathology. Withdrawal from bucillamine and prednisolone treatment made rapid improvement of pemphigus lesions.