Prospective controlled data of lymph node evaluation by endoscopic ultrasound in esophageal, gastric and pancreatic cancer is presented. Lymph node pattern, changes of boundaries and echogenicity were considered. Preoperative findings of endoscopic ultrasound were classified according to TNM staging. Only those cases with subsequent histologic examination of the resected specimen were entered into the study. Sensitivity of endoscopic ultrasonography (EUS) was 90% for esophageal and 87% for gastric cancer. The specificity was 72% and 88%, respectively. In spite of the overall satisfactory results of EUS in evaluation of lymph nodes, further improvement in detection and differentiation of benign and malignant nodes is required.