Early diagnosis by detecting small tumors is essential for improving therapeutic effects on carcinoma of the pancreas. Recently, diagnostic modalities of the carcinoma have greatly advanced, but the clinical usefulness of them has not been elucidated clearly in the early diagnosis. So, we assessed the diagnostic capability of such modalities as ultrasonography (US), endoscopic retrograde cholangiopancreatography (ERCP), X-ray computed tomography (XCT) and angiography in 59 patients with carcinoma of the pancreas surgically resected. Gross- and micro-pathological findings of the resected tumors were studied in all the patients. The tumors were divided into two groups according to the size; the one consisted of 19 tumors sized 2 cm or less and the other did of 40 tumors larger than 2 cm. All the tumors in the small size group were located in the pancreatic head. The detection rate of abnormality about the carcinoma in these modalities was so various in the small size group, while it was almost similar each other in the large size group. Above all, US exhibited the highest capability in detecting small tumors of the pancreas and making the early diagnosis. In conclusion, it may be said that the use of US in combination with laboratory tests of pancreatic enzymes, followed by ERCP when necessary, is the most effective for early diagnosis of pancreatic carcinoma.