An African grey parrot (Psittacus erithacus) was presented with exophthalmos and a semisolid mass dorsomedial to the left eye that led to ventrotemporal deviation of the globe. Ultrasonography of the eye revealed a well-demarcated mass of cystic appearance, retrobulbar to the left eye. Cultures of samples of the mass acquired by fine needle aspiration were negative for bacteria and Mycoplasma species. Metaplasia of a periorbital gland caused by hypovitaminosis A was suspected, and vitamin A supplementation was initiated. Because of unresponsiveness to therapy, the cystic mass was surgically removed. The histologic diagnosis was adenoma. The surgical wound healed well, and no recurrence was observed 10 months later. To our knowledge, this is the first report of surgical removal of a retrobulbar adenoma in this species with the eye remaining intact and functional.