A patient suffering from an ichthyosiform dermatosis, partial deafness, and pes cavus is described. Most of the body surface was covered by fine white scales; red scaling plaques were present on the arms. There were slight hyperkeratoses of the palms and soles, keratosis pilarislike lesions with perifollicular redness on the trunk, and multifocal alopecia. A biopsy specimen of the scaly erythematous plaque demonstrated hyperkeratosis with follicular plugging, papillomatosis, and acanthosis. Direct immunofluorescence studies of lesional skin using monoclonal antibodies to epidermal prekeratin, filaggrin, and involucrin revealed normal staining patterns. The patient's cultured keratinocytes were morphologically unremarkable and contained profilaggrin, involucrin, and a normal complement of cytokeratins. The expression of the disease may not occur in cultured cells, because they lack many features of fully keratinized cells. A review of the literature concerning ichthyosis and deafness reveals that the constellation of cutaneous and extracutaneous abnormalities in this case does not exactly conform to that in previously reported cases. Precise classification of the patient's disorder will require demonstration of the basic defect(s).