We describe two patients with palmar filiform hyperkeratosis, characterized by multiple thin spiny keratotic projections on the palms. The condition has been associated with an underlying malignancy in some cases. One patient has myelofibrosis, an association not previously described. In addition we describe a further patient with filiform hyperkeratoses of both palms and soles with no associated underlying disorder. In view of the relatively high risk of underlying malignancy occurring in patients with filiform hyperkeratosis, these patients should always be investigated fully.