Eighty-seven records of patients with a radiologic diagnosis of benign ulcer, cancer or non-specific gastric changes and with a final diagnosis confirmed by biopsy, surgery or follow-up were analyzed to find out whether gastroscopy was useful. In patients with radiologic diagnosis of benign ulcer, gastroscopy was useful in 87% of the cases. When radiology suspected gastric cancer, gastroscopy established the diagnosis in two thirds of the cases. When the radiologist considered a diagnosis as certain his accuracy and specificity were comparable with those of the endoscopist. In such cases endoscopy is only confirmatory. In 7 patients with a radiologic diagnosis of non-specific gastric changes gastroscopy established diagnosis in 6. We concluded that gastroscopy is useful for the patient with a diagnosis of benign ulcer, non-specific gastric changes, or suspicion of gastric cancer. When diagnosis of gastric cancer is established by radiology, gastroscopy is not useful.