We developed a robot-assisted transmediastinal esophagectomy (RATME) to reduce the surgical invasiveness of open transthoracic esophagectomy (oTTE). However, the long-term survival outcomes of patients who undergo RATME remain unclear. Patients who underwent RATME for esophageal squamous cell carcinoma (ESCC) between January 2012 and April 2020 were enrolled. Overall survival (OS), relapse-free survival (RFS), and ESCC cause-specific survival (CSS) were analyzed according to clinical stage. Survivals were compared between patients who underwent the RATME and oTTE using propensity score matching analysis. One hundred and twenty-seven patients who underwent RATME were included in the analysis. The 3- and 5-year OS rates were 96.2 and 92.1% for cStage I RATME group, 84.8 and 82.3% for cStage II, and 61.8 and 61.8% for cStage III, respectively. The 3- and 5-year RFS rates were 94.3 and 84.3% for cStageI, 71.7 and 69.3% for cStage II, and 5 48.2 and 48.2% for cStage III, respectively. Survival analysis using 74 paired patients showed that the RATME group had better OS and RFS than the oTTE group (p = 0.0028 and p = 0.016, respectively), but equivalent CSS (p = 0.078). The OS of the RATME group stratified by clinical stage was equivalent to that of the comprehensive registry data from Japan, and showed better OS and RFS than the oTTE group, indicating that RATME radicality is guaranteed with regard to long-term survival.