Esophageal involvement by extranodal natural killer (NK)/T cell lymphoma, nasal type, is rare. As a result, esophageal symptoms in these patients might at first be thought to originate from a benign condition, such as viral esophagitis. It is important to note, however, that benign conditions may mask esophageal involvement by lymphoma. Until now, there has been no report documenting esophageal involvement by lymphoma mimicking viral esophagitis in an extranodal NK/T cell lymphoma patient undergoing active treatment. Here, we report a case of esophageal involvement by extranodal NK/T cell lymphoma, nasal type, initially misdiagnosed as Ebstein Barr virus esophagitis. Lymphoma invasion of the esophagus should be considered if esophageal symptoms do not respond to usual medical esophagitis therapy in an extranodal NK/T cell lymphoma, nasal type, patient undergoing chemoradiation.