Purpose: This study aims to elucidate the longitudinal alterations in frailty and health-related quality of life experienced by elderly patients undergoing surgical treatment for esophageal cancer. Additionally, it seeks to ascertain the impact of preoperative frailty on postoperative health-related quality of life over time. Methods: 131 patients were included in the prospective study. Patients' frailty and health-related quality-of-life were assessed utilizing the Tilburg and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 at preoperative, 1 week, 1 month, and 3 months, postoperatively. Statistical analyses were performed using generalized estimating equations, repeated-measures analysis of variance, and linear mixed models (LMMs). Results: Out of 131 patients, 28.2% had frailty before surgery, and the prevalence of frailty consistently higher after surgery compared with baseline (67.9%, 51.9%, and 39.7%). There was no significant change in frailty scores in preoperative frail patients within 3 months following surgery (p = .496, p < .999, p < .999); whereas in preoperative non-frail patients, the frailty scores increased at 1 week (p < .001) and then decreased at 1 month (p = .014), followed by no change at 3 months. In addition, preoperative frail patients had significantly worse global quality-of-life (beta = -4.24 (-8.31; -.18), p = .041), physical functioning (beta = -9.87 (-14.59; -5.16), p < .001), role functioning (beta = -10.04 (-15.76; -4.33), p = .001), and social functioning (beta = -8.58 (-15.49; -1.68), p = .015), compared with non-frail patients. Conclusions: A significant proportion of participants exhibited a high prevalence of preoperative frailty. These patients, who were preoperatively frail, exhibited a marked reduction in health-related quality-of-life, a more gradual recovery across various functional domains, and an increased symptom burden during the follow-up period. Therefore, it is crucial to meticulously identify and closely monitor patients with preoperative frailty for any changes in their postoperative physiology, role, and social functioning.