Gilteritinib is currently approved in China for relapsed/refractory FLT3-mutated acute myeloid leukemia, and it is very important to monitor and report its adverse drug reaction (ADR) after post-marketing. This case report describes a patient who was diagnosed with acute myeloid leukemia harboring FLT3 mutations and developed a severe suspected immune-related enteritis during treatment with gilteritinib for maintenance therapy following allo-hematopoietic stem cell transplantation. According to the Naranjo probability scale, gilteritinib was defined as a 'possible' cause of ADR. Another suspicious inducement, graft-versus-host disease, can not be eluted and might represent a limitation in this case. To the best of our knowledge, this is the first report on gilteritinib-induced severe enteritis and will help physicians to keep vigilant, and detect and deal with time for possible ADR.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.