The Papillon-Lefévre syndrome (PLS) is an autosomal recessive trait characterized by diffuse transgredient palmar-plantar keratosis (PPK) and premature loss of both the deciduous and permanent teeth. In most cases, the PPK is noted within the first 3 years of life. The periodontal lesions begin shortly after the start of both the primary and the permanent dentitions. The teeth are affected in the order of their eruption, exhibiting inflammation of the periodontal tissue, bleeding of the gums, pocket formation, loosening, and finally spontaneous exfoliation without showing definite signs of root resorption. After an edentulous interval, the same process begins anew shortly after the second dentition. Ectopic intracranial calcifications, mental retardation, and increased susceptibility to infections have often been seen in PLS patients and may thus be regarded as facultative signs.