Background Postoperative chylothorax is a rare but life-threatening complication of esophagectomy. However, due to its rarity, researching the risk factors and selecting appropriate treatment options has been limited. Methods This study included 727 patients with esophageal cancer who underwent minimally invasive esophagectomy at our hospital. To detect the risk factors for chylothorax, we divided the patients into two groups, with and without postoperative chylothorax. We then compared patient characteristics, tumor-specific variables, and operative details. Subsequently, we analyzed the peri-treatment characteristics and outcomes for the three distinct treatment options we had chosen: surgery, conversion (the group that finally underwent surgery after unsuccessful conservative treatment), and conservative. Results Of the 727 patients, 18 (2.5%) developed a chylothorax. The mean BMI was lower (20.3 vs. 21.9, p=0.057), and more cases of thoracic duct resection were found in the chylothorax group (33.3% vs. 6.2%, p=0.001), with statistical significance. Multivariate analysis identified thoracic duct resection as a risk factor (adjusted odds ratio, 6.83). The drainage volume two days after chylothorax was higher in the surgery group, although the difference was not statistically significant (surgery group, 1,405 ml vs. conversion group, 260 ml vs. conservative group, 310 ml; p=0.073). The surgery group had the shortest median postoperative hospital days among these groups (21.5 as compared to 102 and 25.0 days in the conversion and conservative groups, respectively; p<0.001). None of the patients died during their hospital stays. Conclusion Thoracic duct resection during the initial minimally invasive esophagectomy was an independent risk factor for chylothorax. If drainage volume does not decrease on the second day, early surgery may lead to earlier discharge.