Papillon-Lefevre syndrome is an extremely rare genodermatosis characterized by palmoplantar keratoderma and premature loss of teeth. It is inherited as an autosomal recessive trait, and is known to be caused by a loss-of-function mutation in the cathepsin C gene. Mutations of this gene may result in epithelial defects producing keratoderma and secondary periodontitis recalcitrant to traditional treatment, causing subsequent premature loss of teeth. In addition, patients may have increased susceptibility to infection. Histopathologic features are nonspecific, so diagnosis has been made through characteristic skin and teeth findings in many reported cases. Oral retinoids are the mainstay of treatment, but the safety of oral retinoids in children remains controversial due to their side effects in skeletal development. Therefore, a multidisciplinary approach is important for the care of patients with this syndrome. We present two cases of Papillon-Lefevre syndrome. To our knowledge, this condition has not been reported previously in the Korean dermatologic literature. (Korean J Dermatol 2009;47(4):472~478)