736 Background: To elucidate the toxicity and survival outcome of neoadjuvant chemoradiotherapy (CRT) followed by curative total mesorectal excision (TME) in elderly rectal cancer patients compared to younger patients. Methods: A total of 1232 rectal cancer patients who received neoadjuvant CRT and curative surgery were collected from 7 tertiary institutions. After propensity-score matching, 310 patients of < 70 years for younger arm and 310 patients of ≥ 70 years for elderly arm were identified, respectively and matched with 1:1 manner. Treatment response and toxicity, surgical outcome, recurrence, and survival were assessed and compared between two arms. Results: The two younger (< 70 years) and elderly (≥ 70 years) arms were well-matched and had similar baseline characteristics. Median ages were 58 years for younger arm and 74 years for elderly arm, respectively. Pathologic complete response rates were not significantly different between younger arm and elderly arm (17.1% vs. 14.8%, P = 0.443). The 5-year recurrence-free survival (70.0% vs. 69.8%, P = 0.773) and overall survival (79.5% vs. 82.9%, P = 0.270) rates were not significantly different between two arms. Adjuvant chemotherapy after surgery was less frequently delivered to elderly arm than younger arm (69.0% vs. 83.9%, P = 0.773). Grade 3 or higher acute hematologic toxicity was observed more frequently in elderly arm than in younger arm (9.0% vs. 16.1%, P = 0.008 ), but late complication was not significantly increased in elderly arm (2.6% vs. 4.5%, P = 0.193). Conclusions: Despite an increased acute toxicity, elderly rectal cancer patients with good performance status would have equivalent tumor response and recurrence-free survival compared to younger patients.