Adjuvant tegafur-uracil therapy has prolonged postoperative survival in patients with non-small cell lung cancer. Some patients experience treatment discontinuation due to gastrointestinal disorders such as anorexia, and the associated factors and the impact of lobectomy remain unclear. This study aimed to assess the postoperative esophageal displacement after lobectomy and to clarify its impact on the continuity of tegafur-uracil treatment. Patients who received adjuvant tegafur-uracil therapy after lobectomy between April 2009 and March 2019 were retrospectively analyzed. Patient background, perioperative characteristics, treatment findings, and the degree of esophageal displacement measured by computed tomography were compared between the treatment completion group and the discontinuation group. A subgroup comparative analysis was further performed in the groups divided according to the degree of esophageal displacement. A total of 68 patients were reviewed, including 41 males and 27 females with a mean age of 66.2 years old. A total of 41 patients completed the 2-year adjuvant treatment and 27 patients discontinued it. The overall survival and relapse-free survival between the two groups were statistically significant (p = 0.027, p = 0.010). The degree of esophageal displacement at the Th7 level was a significant predictor of treatment discontinuation (p = 0.046, odds ratio [OR]: 1.138, 95% confidence interval [CI]: 1.002-1.291). Among the patients with a high degree of esophageal displacement above the baseline determined from the receiver operating characteristic curve, the cause of discontinuation was anorexia, which was significant in multivariate analysis (p = 0.013, OR: 14.72, 95% CI: 1.745-124.2). Our study suggested that anatomical displacement of the esophagus after lobectomy may affect the discontinuation of oral adjuvant chemotherapy in patients with lung cancer.