Immunoglobulin G4-related sclerosing disease (IgG4-SD) is currently recognized as a distinct systemic disease involving various organs. We reported the imaging findings of a case of pathologically confirmed IgG4-SD involving bilateral palatine tonsils. CT and MRI showed diffuse enlargement of both palatine tonsils with homogeneous contrast enhancement. Focal contour bulging was noted in the right palatine tonsil. Lesions appeared as isointense on T1-weighted and slightly hyperintense on T2-weighted MRI images, as compared with muscle. The T2-weighted MRI image showed a striated pattern in both tonsils. Despite its rare occurrence, IgG4-SD should be included in the differential diagnoses of patients with symptomatic bilateral tonsillar hypertrophy that is non-responsive to medication.