Abstract: Objective To evaluate the use of dual-phase helical CT in early detection and correct staging of small pancreatic adenocacinoma. Methods Dual-phase helical CT was performed on 14 patients with small pancreatic adenocacinoma with 100 ml intravenous contrast material injected at a rate of 3 ml/s. Pancreatic phase(PP) and portal venous phase(PVP) began at 30 seconds and 65 seconds after the start of the injection respectively. The enhancement of normal pancreas and tumor during the two phases was observed and compared. The assessment of tumor resectability based on CT findings was compared with surgical and histopathologic results. Results Tumor-pancreas contrast was significantly greater in PP (47.08±20.39) HU than in PVP (28.77±16.23) HU (t=2.533, P<0.01). 11 of 14 tumors were thought of resectable before operation, 9 were actually resected in the operation. Conclusion Dual-phase helical CT could delineate small pancreatic adenocarcinoma clearly and afford more information for the diagnosis and the assessment of resectability of the lesion. The tumor-pancreas contrast was much better in PP than in PVP.