We report a large kindred in which palmoplantar keratoderma occurred in association with breast or ovarian cancer or both. This kindred consisted of 61 members of four generations. Thirty-five individuals had palmoplantar keratoderma, including eight women who also had breast or ovarian cancer or both. Five of the six women with breast cancer and both the women with ovarian cancer have died. The proband presented with a yellowish, uniform hyperkeratosis surrounded by a red border covering the entire surface of the palms and soles. Light microscopic examination showed features of epidermolytic hyperkeratosis, and ultrastructural examination revealed the typical markers for this entity, cytolysis and clumps of keratin filaments. This kindred is the first, to our knowledge, to have an association of epidermolytic hyperkeratosis and internal malignancy.