Five cases of a syndrome previously reported as Cowden's disease are reported. The disorder is composed of a complex mixture of ectodermal, mesodermal, and endodermal hamartomatous lesions of which mucocutaneous, breast, thyroid, and gastrointestinal tumors are most often encountered. The mucocutaneous lesions are thought to represent the most distinctive elements of this syndrome and consist of lichenoid and papillomatous lesions of the face and ears, acrokeratotic lesions of the hands, papillomatous and papular oral lesions, multiple lipomas, and angiomas. The histologie findings suggest that the cutaneous lesions of the ears and face are hamartomas of hair follicle origin similar to inverted follicular keratosis. The disorder is tentatively identified as a dominantly inherited disorder with no chromosomal abnormalities identifiable. The name multiple hamartoma syndrome is proposed as a more precise one for this unique disorder.