Acquired periungual fibrokeratomas are rare, benign, fibrous and hyperkeratotic tumours. They usually present as lesions which emerge from the proximal nail fold, or sometimes from the nail bed. Although acquired periungual fibrokeratoma is considered as a topographical variant of acquired digital fibrokeratoma, it has a unique "garlic-clove" shape and causes nail deformity. We present herein a case of acquired periungual fibrokeratoma occurring beneath the proximal nail fold. Histologically, an accessory germinal matrix was observed at the distal end of the lesion. Change in pressure around the lesion seemed to have induced the formation of this accessory germinal matrix. (Korean J Dermatol 2003;41(8) : 1068~1071)