The authors report a case of retro-pancreatic tumor in a 65 year-old man associated with impaired general condition. At gross examination by the surgeon, the pancreatic gland seemed to be enlarged. Histologic analysis found fibrous tissue and inflammation with lymphoid cells. The diagnosis of inflammatory pseudotumor was based on similar aspects found in some orbital lesions. The "tumor" disappeared under steroid therapy but recurred as soon as the treatment was stopped. Several etiologic factors related to the unusual location of the lesion were discussed.