We report a case of Epstein-Barr virus (EBV)-associated T-cell lymphoma of gastrointestinal (GI) tract from a 70-year-old white woman who initially presented with a widespread GI inflammation and gastric obstruction. Initial biopsies of the GI tract showed severe chronic inflammation in the esophagus, stomach, and the small intestine. Celiac disease and inflammatory bowel disease were ruled out. The patient was treated with partial gastrectomy. Histology showed gastric wall thickening with EBV-positive, mixed lymphocytic and plasma cell infiltration in the mucosa, and thickening and fibrosis of the submucosa. She developed EBV-associated T-cell lymphoma of the GI tract one and a half years later and expired due to multiorgan failure. The T-cell lymphoma diffusely infiltrated the GI wall without forming a mass lesion. The lymphoma expressed EBV and cytotoxic molecules but lacked common features of extranodal natural killer/T-cell lymphoma nasal type, such as angioinvasion/angiodestruction, necrosis, or CD56 expression. Immunoglobulin heavy chain (IGH) gene and T-cell receptor-γ gene rearrangements and EBV-positive cells were detected at the early stage of the disease. While IGH clones were transient, T-cell clones and EBV-positive cells progressively increased over the disease course. We conclude that this case is best classified as EBV-associated peripheral T-cell lymphoma of GI tract. Age-related immune senescence may have contributed to the uncontrolled GI inflammation and subsequent transformation to T-cell lymphoma.