A 69-year-old man with chief complaint of epigastralgia was diagnosed as locally advanced borderline unresectable pancreatic head cancer that involved superior membrane artery (SMA). Gemcitabine (GEM) -based chemoradiotherapy (CRT) was administered for consecutive 3 weeks in the following fashion: continuous twice-a-day accelerated radiotherapy (2 daily fractions of 1.5 Gy, 5 days a week, with a 6-hr minimal interval between fractions) with 3-time weekly intravenous infusions of GEM. Total radiation dose was 45 Gy and GEM was given on days 1, 8 and 15 at dose of 800 mg/m2. After the completion of CRT, the involvement of SMA remained. Next, additional systemic chemotherapy with GEM was performed for 3 weeks in the following fashion: weekly intravenous infusions of GEM at dose of 1,000 mg/m2. Finally, the main tumor and the invasion to SMA were reduced. Surgical resection with negative margins (R0 resection) was performed. Adjuvant chemotherapy with 6 courses of GEM was also performed. The patient has no recurrence, suggesting the efficacy of GEM-based CRT for locally advanced borderline unresectable pancreatic cancer.