Following a simple cholecystectomy, a 63-year-old woman with gallstones was histologically diagnosed as having minute squamous cell carcinoma of the gallbladder. A laparotomy revealed a small, firm nodule that appeared to be an adenoma, which was palpated in the fundus of the gallbladder. The resected gallbladder contained 37 small stones and a small and firm mass (0.4 x 0.4 x 0.3 cm in size) on the mucosal side. Histologically, a pure type of well-differentiated squamous cell carcinoma of the gallbladder was diagnosed. To our knowledge, this is the first case of a minute and pure type of squamous cell carcinoma in the gallbladder. This case may have implications for the histogenesis of squamous cell carcinoma of the gallbladder.