A case of a 75 year-old male with primary squamous cell carcinoma of the stomach is reported. It is extremely rare to see squamous cell carcinoma developing in the stomach, without being accompanied by a component of adenocarcinoma. Up to the present, 18 Japanese and 62 Western cases of this type of carcinoma have been reported in the literature. The origin of this malignancy has not been well elucidated yet and thus, several plausible hypotheses have been proposed. In this presented case, the tumor consisted of only squamous cell carcinoma and the focus of squamous metaplasia was not found histologically in the adjacent mucosa. Therefore, it may be considered that the carcinoma arises from misplaced squamous cell nests of the stomach.