A 22-yr-old, female gray-banded kingsnake (Lampropeltis alterna) was examined for stomatitis and hard ventral scales. On examination, the ventral scales palpated as rigid and brittle. A blood sample yielded marked hypovitaminosis D (11 nmol/L). Radiographs revealed a generalized bone radiopacity outlining the ventral scales; scale biopsies were obtained for histologic examination and presented linear, superficial, and midzonal foci of well-differentiated dermal bone and bone marrow. The stomatitis was successfully treated, but the general condition of the snake declined, and it was euthanized. The most significant finding in the postmortem examination was abnormally pale kidneys. Histologic examination revealed diffuse renal gout and diffuse osseous metaplasia in the dermis of all of the ventral scales. Generalized osseous metaplasia of the ventral scales in snakes has not, to our knowledge, been reported; the cause in this report was not identified, but given the extensiveness of the lesion, it is likely that the cause was multifactorial.