OBJECTIVE. Recent studies have shown evaluation of the small peripancreatic veins to have potential in improving pancreatic cancer staging. This study was performed to determine the effectiveness of thin- section pancreatic phase helical CT images in visualizing these veins. MATERIALS AND METHODS. Seventy-two patients (30 with pancreatic adenocarcinoma and 42 with no pancreatic disease) underwent dual-phase helical CT with thin-section pancreatic phase acquisition (40-70 sec after IV contrast initiation at 3 ml/sec) and hepatic phase acquisition (70-100 sec). Visualization (with diameter measurement) or nonvisualization of the posterior superior pancreaticoduodenal vein (PSPDV), anterior superior pancreaticoduodenal vein (ASPDV), and gastrocolic trunk was recorded for both acquisitions. We also correlated surgical tumor resectability with the status of the small peripancreatic veins. RESULTS. Visualization of peripancreatic veins was significantly better on pancreatic phase images than on hepatic phase images for both healthy individuals (PSPDV, 88% of the veins visualized on the pancreatic phase images versus 50% on the hepatic phase images; ASPDV, 93% on the pancreatic phase images versus 48% on the hepatic phase images; gastrocolic trunk, 98% on the pancreatic phase images versus 76% on the hepatic phase images) and for pancreatic cancer patients (PSPDV, 97% on the pancreatic phase images versus 57% on the hepatic phase images; ASPDV, 77% on the pancreatic phase images versus 43% on the hepatic phase images) (p < .05). The exception was the gastrocolic trunk in cancer patients (83% on the pancreatic phase images versus 77% on the hepatic phase images) (p > .05). In pancreatic cancer patients, 11 dilated peripancreatic veins were identified on the pancreatic phase images compared with six on the hepatic phase images. However, only one of the 11 dilated peripancreatic veins was in a patient with surgically resectable disease. CONCLUSION. In a dual-phase helical CT protocol, thin-section pancreatic phase images provided visualization of the small peripancreatic veins that was superior to hepatic phase images, providing further support for the use of this protocol in pancreatic cancer evaluation.