A 10-year-old male fossa (Crytoprocta ferox) exhibited clinical signs of diarrhea, anorexia and weight loss. Chemistry values and echographic results were suggestive of intestinal lymphoma. Postmortem examination revealed severe multifocal wall thickening of the small intestine with severe enlargement of the pancreatic lymph node. Microscopically, the small intestine was multifocally transmurally infiltrated by large neoplastic round cells also found in the pancreatic lymph node and the liver. On immunohistochemistry, the neoplastic cells stained intensely with CD3 and didn’t stain with CD79a. Based on these findings, a diagnosis of intestinal T-cell lymphoma with pancreatic lymph node and liver involvement was made. To the authors’ knowledge, this is the first report of a lymphoma with immunohistochemical phenotyping in a fossa.