A differential diagnosis of an ulcer on the hard palate must consider a wide variety of diseases and conditions, among them rare entities such as necrotizing sialometaplasia. We report the case of a patient who presented with a painful ulcer on the hard palate. A biopsy taken at the initial presentation of the patient revealed a diagnosis of necrotizing sialometaplasia. Histology showed foci of eosinophilic granulocytes with lobular infarction or necrosis, bland-appearing nuclear morphology of squamous cells, simultaneous metaplasia of ducts and mucous acini. The ulcer resolved spontaneously within seven weeks and required no specific treatment. The case presented here shows that early diagnosis of necrotizing sialometaplasia is important in order to prevent unnecessary treatment.