Bullous pemphigoid (BP) is an acquired autoimmune disease that`s characterized by subepidermal vesicles and bullae. The etiology for BP is mostly idiopathic, but numerous observations have suggested the role of certain drugs in the occurrence of bullous pemphigoid. Drugs such as penicillamine, furosemide, captopril, enalapril, sulfasalazine and ampicilline have been reported to be associated with bullous pemphigoid. We report here on a new case of bullous pemphigoid that was probably induced by ticlopidine (thienopyridine, adenosine diphosphate receptor inhibitor) in a 78 year old female patient. (Korean J Dermatol 2009;47(9):1019∼1023)