Hyperadrenocorticism was diagnosed in three related teddy bear hamsters with presenting complaints of alopecia and hyperpigmentation of the skin. Treatment was attempted in two of the hamsters and was successful in one case. Metyrapone and o,p'-DDD (1,1-dichloro-2-2bis (p-chlorophenyl) ethane) were the drugs used. Necropsy and histopathological examinations revealed a pituitary chromophobe adenoma in one hamster and an adrenocortical adenocarcinoma in a second hamster. The third related hamster was clinically diagnosed as having hyperadrenocorticism but the origin of the disease has not yet been determined.