Endoscopy, biopsy, and cytology represent the gold standard for the diagnosis of gastric malignancies. Guidelines have been developed to select the patient-population at risk of gastric cancer as well as for the appropriateness of endoscopic examination among large gastric cancer screening programs. Endoscopic ultrasound is an essential part of preoperative staging in view of gastric resection and may be useful to identify high-risk patients potentially eligible for investigational neoadjuvant treatment programs. Some of the current issues in endoscopic diagnosis and staging of gastric tumors are reviewed.