Both multiple endocrine neoplasia type 1 (MEN1)-related gastrinomas and gastrointestinal stromal tumors (GISTs) are rare neoplasms, and their association has been rarely reported. We describe an unusual association between a GIST and a MEN1-related gastrinoma. A 44-year-old man had undergone surgical removal of a pancreatic gastrinoma in 2004 and was then administered long-term somatostatin analogs, and diagnosed as having MEN1 syndrome. Following an uneventful follow-up, in April 2009, an upper gastrointestinal tract endoscopy showed esophageal narrowing, with evidence of a 2-cm solid mass on endoscopic ultrasonography. Histology revealed a tumor composed of elongated cells with plump cytoplasm arranged in a storiform pattern. The immunophenotype of the lesion was CD117 and Platelet Derived Growth Factor (PDGF) positive, whereas alpha-1 muscle actin and S-100 protein were negative. Due to morphological and immunohistochemical results, a final diagnosis of esophageal GIST was made. The association between GISTs and MEN1 could be casual, although a single case of the coexistence of a GIST and a MEN1-related gastrinoma has already been reported. A role of the MEN1 gene in the pathogenesis of GISTs could be hypothesized.