Benign mesenchymoma is an extremely rare neoplasm mostly located in or about the kidney and is composed of a haphazard mixture of adult fat, fibrous tissue and tangled blood vessels, scattered nests or masses of smooth muscle cells, occasionally islands of cartilage, bone, and lymphoid tissue as well as other mesenchymal elements. Only two cases of benign mediastinal mesenchymomas were reported in the literature. In this report we describe a benign mesenchymoma of the mediastinum which presented itself with symptoms and signs of the traction diverticula of the esophagus.