Recent advance in various diagnostic imagings has enabled the early diagnosis of pancreatic tumors. In pancreatic cancer, the tumor-demonstrability by US, CT, and MRI has reached 80% in the recent 6 years, which is superior to the rate in the past decade from 1978 and 1987. However, the prognosis of pancreatic cancer is still poor even if the cancer can be resected. To improve the outcome of surgical intervention, early detection of small cancers (< or = 2 cm in diameter) and appropriate intervention based on preoperative diagnosis of the tumor extension are proposed. The tumor detectability of small pancreatic cancer by US, CT, MRI was 67%, 25%, 20%, respectively, and thus US was the most valuable tool. In the prediction of tumor extension of serosal invasion (S factor), retroperitoneal invasion (Rp factor) and vessel invasion (PV factor), both US and CT were efficacious with an accuracy of more than 70%. In conclusion, recently-advanced imaging seems to be useful for detecting a small pancreatic cancer and evaluating the tumor extension, but it remains difficult to diagnose a carcinoma in situ; a truly early cancer.