An abnormally large tonsil may be a sign of malignancy. We retrospectively analyzed the case files of 87 patients who had asymmetrically sized but otherwise normal tonsils and no risk factors for cancer to determine if asymmetry is associated with a higher incidence of malignancy. We found 2 cases (2.3%) of malignancy among these patients. One patient had high-grade non-Hodgkin's lymphoma in the larger tonsil, and the other had lymphocyte-rich Hodgkin's lymphoma. Both patients were older than 50 years, and neither had a history of recurrent tonsillitis. We believe that although the incidence of cancer in our series was small, it is significant. Therefore, we recommend routine excision of abnormally large tonsils. Moreover, when making such a recommendation to a patient, it is essential that the patient have a clear understanding of the risk and benefit of having a tonsil removed solely because of asymmetry.