Abstract Background The number of esophagogastric junction (EGJ) cancers has been increasing in recent years, and the trans hiatal lower esophagectomy is widely used for cases with shorter esophageal invasion. However, the mediastinal surgical view through the hiatus is sometimes poor due to cardiac compression, and resection and reconstruction are often difficult in these cases. We therefore retrospectively examined the influence of cardiac diameter on short-term postoperative outcomes. Methods From June 2004 to December 2022, 97 patients underwent radical surgery for EGJ cancer at our hospital, of those 67 patients underwent trans-hiatal approach. We retrospectively analyzed the relationship between cardiothoracic ratio (CTR) on preoperative chest radiographs and left ventricular diastolic diameter (LVDd) on echocardiography and postoperative complications in patients underwent trans hiatal approach. Results Patients with preoperative CTR >50% had a significantly higher rate of anastomotic leakage (33% v.s. 7%, p<0.05), and similarly for LVDd, when divided into two groups using 43 mm as cut-off, patients with larger heart diameter had significantly more anastomotic leakage (69% v.s. 24%, p<0.05). We performed a multivariate analysis using CTR, ASA-PS, blood loss, operative time, BMI, and tumor diameter, and defined CTR as an independent risk factor for anastomotic leakage (OR: 7.76, 95%CI: 1.45-41.4, p<0.05). Conclusion Trans-hiatal approach can be used for resection of EGJ cancer. However, special attention should be paid to the prevention of anastomotic leakage in patients with cardiac comorbidities or a large preoperative CTR or LVDd.