While chemoradiotherapy (CRT) is commonly employed as a curative approach for esophageal cancer, administering standard CRT to elderly patients often presents challenges in practical settings. The objective of this study was to compare treatment tolerance and survival outcomes between younger and elderly patients (aged ≥65 years) diagnosed with locally advanced esophageal cancer receiving curative-intent treatment. Additionally, it aims to assess the impact of the Geriatric 8 Health Status Screening Tool (G8 score) on treatment decisions in elderly patients. Ninety-seven patients treated with neoadjuvant or definitive CRT for locally advanced esophageal cancer were retrospectively evaluated at two centers from 2013 to 2023. We divided the patients by age (<65 and ≥65 years) and assessed their demographic, clinical, and treatment data, including pre- and post-treatment G8 scores. Radiotherapy (RT) was administered at a median dose of 50.4 Gy (45-66 Gy). Planned concurrent chemotherapy was completed in 73 (75.3%) of the patients. In the comparative study of 97 esophageal cancer patients, 48 geriatric (aged ≥65 years) and 49 younger individuals were followed up for a median of 20 and 21 months respectively. No significant statistical differences were noted between the groups concerning baseline and treatment characteristics. Surgical intervention rates were comparable, with 22.9% of geriatric and 36.7% of young patients undergoing surgery (p=0.184). There were no significant differences in pathological complete response, local recurrence, distant metastasis, progression, or death rates. The median progression-free survival (PFS) for geriatric and younger patients was 31 months (95% CI, 13.6-48.4) and 19 months (95% CI, 0-39.4), respectively (p=0.832). The median overall survival (OS) was 38 months (95% CI, 23.8-52.2) in geriatric patients, while it was not reached in younger patients (p=0.745). There was no significant difference between the two groups. The pretreatment and posttreatment G8 values of the geriatric patients were 9.25 (6-13.5) and 9.5 (6-14), respectively. Patients with increased G8 scores were found to have significantly higher PFS (median 85 mo vs. 11 mo, p=0.001) and OS (median 85 mo vs. 14 mo, p=0.001) compared to those with unchanged or decreased G8 scores. Age alone should not be the determining factor in the treatment decision of elderly patients diagnosed with locally advanced esophageal cancer. Moreover, CRT could be safely performed even in patients with low G8 scores, and although the G8 score may not directly influence treatment decision, its enhancement during the treatment process holds significant prognostic value.