Accurate preoperative staging is now more prerequisite in the management of cancer of the pancreas and ampulla in order to orientate the patient toward the best selected treatment: either a curative or a palliative surgery associated or not with a pre- or postoperative multimodal therapy, or an endoscopic palliative technique which does not require surgery. Endoscopic ultrasonography (EUS) appears to be a highly accurate diagnostic procedure in the assessment of local resectability because it enables detailed visualization of the pancreatic gland, the depth of infiltration into the surrounding tissue and organs and visualisation of regional lymph nodes involvement. EUS-guided fine needle aspiration for cytology will provide a tissue diagnosis. The likelihood of successful resection for palliative or cure can be predicted before surgery. The following overview will point out the clinical impact of EUS on diagnosis, staging and management of these tumors.