The inherited palmoplantar keratodermas (PPK) may be associated with a wide variety of other ectodermal abnormalities. The coexistence of PPK and leucoplakia may indicate the increased risk of oesophageal carcinoma in adult life. Cutaneous horn may develop over benign, precancerous, as well as malignant lesions, and frequently may be associated with actinic keratoses and Bowen's disease. On the other hand, the relationship of cutaneous horn and leucoplakia has been the subject of only a single case report. We present a case of PPK and diffuse oral leucokeratosis associated with relapsing cutaneous horn of the lips.