Myospherulosis is a recently discovered iatrogenic disease caused by the implantation during surgery of mineral oil- or petrolatum-based products into various tissues. The condition results from the action of lipid substances on extravasated erythrocytes. The case report presented is the first detailed description of this uncommon, unique inflammatory lesion occurring in the mastoid and is the second otitic case reported in the literature. The lesion mimicked recurrent cholesteatoma 6 years following an intact canal wall mastoidectomy. As in myospherulosis of the paranasal sinuses, the symptoms and findings of otitic myospherulosis are those of the preceding disease.