We report a case of a 76-year-old female with unresectable advanced pancreatic tail cancer in whom systemic chemotherapy using gemcitabine hydrochloride was effective. The patient came to our hospital with a complaint of upper abdominal discomfort and was diagnosed as an advanced pancreatic tail cancer with severe vessel invasion. A curative operation was thought to be impossible, so gemcitabine hydrochloride was administered (800 mg/m2/week x 3/4 weeks). After 2 courses, the CEA, CA19-9 and SPan-1 value were decreased, and reduced tumor size was identified. Sixteen months after the first diagnosis, she died dissemination.