Pneumatosis intestinalis (PI) is an uncommon disease defined as gas-filled cysts that are found in the wall of the gastrointestinal (GI) tract. The exact causes of PI are still unclear, but it may associated with coexisting diseases, such as some GI disorders, connective tissue disease, some medication and drugs, and rarely malignancy. The most common localization is the small intestine. Gastric PI secondary to malignancy has been rarely documented. We report on a 94-year-old man with gastric PI associated with inoperable adenocarcinoma localized in the duodenum. Following the gastrojejunostomy and choledochojejunostomy bypass, his general condition improved and PI disappeared, but he died due to poor performance status and malignancy 6 mo later. We suggest that in patients presenting with PI, malignancy should be considered in the differential diagnosis. (C) 2009 The WJG Press and Baishideng. All rights reserved.