Immunoglobulin G4-related disease (IgG4-RD) and immunoglobulin G4-related ophthalmic disease (IgG4-ROD) complicated with nonlymphoid malignancy (NL-malignancy) are rare. No exact relationship between IgG4-RD and NL-malignancies has been established yet, and there have been few reports of different types of IgG4-ROD and related malignancies.We retrospectively reviewed medical records of patients diagnosed with IgG4-RD and NL-malignancy, whichever occurred first, from January 2015 to March 2021. In addition, the literature on the relationship between IgG4-ROD and NL-malignancy was reviewed.There were 115 patients diagnosed with IgG4-RD, and 10 patients were enrolled in the study with NL-malignancy. Three patients were diagnosed with IgG4-ROD. One patient reported a previous history of cancer, and the other 2 patients developed cancer at or after the diagnosis of IgG4-RD. The 3 patients' cancers were located in the lung, gastrointestinal tract, and thyroid.There may be potential malignancy occurrence during follow-up of IgG4-RD patients, especially among elderly patients. In addition, IgG4-RD could be a paraneoplastic syndrome at or before the diagnosis of malignancy.Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the North American Neuro-Opthalmology Society.