This is a single arm, non-randomized phase II study. Eligible, fully registered patients will receive preoperative chemotherapy consisting of gemcitabine plus erlotinib. Preoperative chemotherapy will be followed by exploratory laparotomy and pancreaticoduodenectomy. Patients will then receive postoperative chemotherapy consisting of gemcitabine plus erlotinib. Up to 123 patients will be accrued to this study, with the expectation that 78 patients will remain fully eligible and evaluable for the primary endpoint. The primary and secondary objectives for the study are listed below.