In the author's experience, malignancy suspected in cases of inflamatory hyperplasia of the right buccal mucosa due to chronic irritation of a denture, usually an ill-fitting denture, is not uncommon. A 74-year-old male with a graysh white mass (2.0×2.0×0.5cm) who had a deep central ulceration which formed against the sharp border of an ill-fitting denture he had used for 4 months, was examined on December 30th of 1977, and a chronic nonspecific inflamation was verified histopathologically.