The case of a patient with a lacrimal fossa mass that was believed to be a primary lacrimal gland tumor is reported. However, at lateral orbitotomy the tumor was found within the lacrimal fossa, but distinct from the lacrimal gland. Histopathology revealed a benign fibrous histiocytoma. The tumor was totally excised, has not recurred over a 3-year follow-up period. This mesenchymal tumor should be included in the differential diagnosis of lacrimal fossa mass in adults.