The effectiveness of lymph node dissection tends to be reduced clinically in elderly patients with colorectal cancer because of physical limitations, such as comorbidities and organ dysfunction. We investigated the influence of the level of lymph node dissection on the prognosis of elderly patients with colorectal cancer. A total of 137 patients with pT2 or more-advanced tumors or lymph node metastasis were retrospectively studied. The 5-year overall survival(OS)andrelapse free survival(RFS) rates were 74.1% and 63.9%, respectively. Lymph node dissection was an independent prognostic factor in the examination of prognostic factors of OS. In the propensity-matchedcohort, the 5-year OS rates were 87.2% and5 8.2%(p=0.02), and the 5-year RFS rates were 77.8% and4 6.4%(p=0.03)in the D3 andred ucedgroups, respectively. The D3 group hada significantly better prognosis than the reduced group. D3 lymph node dissection might contribute to the improvement of prognosis in elderly people with colorectal cancer.