Background/Aim: Currently, there are no standard guidelines for the waiting time from the diagnosis of gastric neoplasms to endoscopic submucosal dissection (ESD). Patients and Methods: A total of 1,605 patients who had undergone ESD for early gastric cancer (EGC) or high-grade dysplasia (HGD) were enrolled. Waiting time for ESD was defined as the time from the first diagnosis to ESD. Multivariable logistic regression analysis was conducted. Results: The curative resection rate was 86.8% and the mean waiting time was 36.8 days. In the multivariable model, longer waiting time did not significantly affect non-curative resection, whereas age >70 years, submucosal fibrosis, and initial cancer diagnosis were significantly associated with non-curative resection. Waiting time was still not identified as a risk factor for non-curative resection in EGC and HGD groups. Conclusion: A longer waiting time from diagnosis to ESD was not associated with non-curative resection.