Ae opposed to most other drug eruptions, drug-induced pemphigus may not develop for at least several months following the initiation of therapy with the offending agent. Unlike sporadically occuring pemphigus, the clinical and hietopathologic patterns of drug-induced pemphigus are most often those of pemphigus foliaceus. We report a case of diphenylhydantoin-induced pemphigus occuring in 30-year-old male with epilepsy. A few coinsized erythematous scaly patches developed on his fae, chest, snd left wrist, and two flaccid bullae on erythemstous base developed on his abdomen after three years snd nine months of therapy with diphenylhydantcin. Histopathologicslly, a biopsy specimin taken from a bullous lesion revealed that bulla is formed just beneath the granular layer and aeaitholytic cells are seen within the bulla. Direct and indirect irnmunofluorescence studies showed regitive findings. Administration of diphenylhydantoin was discontinued and he was treated with systemi and topical corticoeteroid. After 4 weeks, the skin lesions were healed with postinflammatory hysroigmentation and no new lesions were developed thereafter. (Kor J Dermatol 1994; 32(4): 724-728)