Chrysomya bezziana is a causative agent of obligatory myiasis. We report the first case of human infestation of Chrysomya bezziana in Hong Kong in an 89-year-old woman who had previously had a stroke. One day after hospital admission for fever, a small fissure at the labial gingiva of the upper incisors and several ulcerative lesions at the hard palate were noticed during routine mouth care. A live maggot was seen protruding from the small fissure. In the following few days, a total of seven maggots were removed by forceps. Urgent computed tomography and magnetic resonance imaging of the oral cavity showed an ulcerative soft-tissue lesion over the anterior palate, with a fistula communicating to the labial gingiva. The tissue loss was limited to the bony margin of the hard palate. The infestation was managed by manual removal of maggots and surgical debridement. Medical personnel taking care of old or debilitated patients need to bear in mind the possibility of Chrysomya bezziana infestation to be able to make a prompt diagnosis and implement relevant intervention to prevent extensive tissue destruction.