Background/Aims: Repeat endoscopy with biopsy is often performed in patients with previously diagnosed gastric cancer to determine further treatment plans. However, biopsy results may differ from the original pathologic report. We reviewed patients who had a negative biopsy after referral for gastric cancer. Methods: A total of 116 patients with negative biopsy results after referral for biopsy-proven gastric cancer were enrolled. Outside pathology slides were reviewed. Images of the first and second endoscopic examinations were reviewed. We reviewed the clinical history from referral to the final treatment. Results: Eighty-eight patients (76%) arrived with information about the lesion from the referring physician. Among 96 patients with available outside slides, the rate of interobserver variation was 24%. Endoscopy was repeated at our institution; 85 patients (73%) were found to have definite lesions, whereas 31 patients (27%) had indeterminate lesions. In the group with definite lesions, 71% of the lesions were depressed in shape. The most common cause of a negative biopsy was mistargeting. In the group with indeterminate lesions, 94% had insufficient information. All patients with adequate follow-up were successfully treated based on the findings in the follow-up endoscopy. Conclusions: A negative biopsy after referral for biopsy-proven gastric cancer is mainly caused by mistargeting and insufficient information during the referral.