Protein-losing enteropathy (PLE) is a rare syndrome of gastrointestinal protein loss that may complicate a variety of diseases. The primary causes can be divided into erosive gastrointestinal disorders, nonerosive gastrointestinal disorders, and disorders involving increased central venous pressure or mesenteric lymphatic obstruction. Herein, we report on a 65-year-old man with PLE caused by invasive gastrointestinal stromal tumor (GIST). To our best knowledge, this is the first reported association between GIST and PLE. A brief review of the literature on the incidence, pathogenesis and management of GIST is also presented.