Introduction: The insertion of a high-resolution manometry (HRM) catheter into the stomach is essential for accurate manometric diagnoses; however, it is impossible in some cases due to the inability to traverse the esophagogastric junction (EGJ). Predictive factors for these patients have not been investigated in detail, necessitating time-consuming and burdensome procedures for investigators and patients. Therefore, the present study investigated the percentage of and risk factors for failed intubation at the EGJ. Methods: We initially reviewed the medical charts of consecutive HRM procedures performed at our hospital between September 2018 and January 2023. Patient characteristics and the findings of endoscopy and esophagography (where available) were compared between successful and failed procedures. A multivariate logistic regression analysis was conducted to identify predictive factors for the inability to traverse the EGJ. We then validated the predictive factors identified by reviewing consecutive procedures performed between February 2023 and August 2023. Results: Among the 781 procedures performed, 55 (7.0%) failed due to the inability to traverse the EGJ. Achalasia was the most common disorder in these procedures. An older age and dilated esophagus of >34 mm were independent predictive factors for the inability to traverse the EGJ in patients with treatment-naïve achalasia. In the validation study, 7 out of 68 procedures (10.3%) failed due to the inability to traverse the EGJ. A flowchart using the findings of endoscopy and an esophageal diameter of >34 mm predicted the inability to traverse the EGJ with a sensitivity of 71.4% and specificity of 86.9%. Conclusion: Based on an esophageal diameter >34 mm and endoscopic findings, we predicted the inability to traverse the EGJ in more than 70% of patients. A multi-center prospective study is warranted in the future.