Background: The neutrophil-to-lymphocyte ratio is a significant prognostic marker in resectable colorectal cancer; however, there are no equivalent findings for perforated colon cancer. Using our colorectal cancer database, we retrospectively analyzed the data from 1995 to 2015 to determine whether the preoperative neutrophil-to-lymphocyte ratio is associated with survival outcomes in patients with perforated colon cancer.Methods: One-to-one propensity score matching was applied to minimize the difference between the high (>5) and low (≤5) neutrophil-to-lymphocyte ratio groups. Clinicopathological factors, long-term overall survival, and disease-free survival were analyzed and compared between the two groups. The primary outcomes were overall survival and disease-free survival.Results: Before propensity score matching, the high neutrophil-to-lymphocyte ratio group had a significantly higher prevalence of leukocytosis (low vs. high neutrophil-to-lymphocyte ratio groups: 12 [12.9%] vs. 46 [59.7%], p<0.001), lower serum albumin levels (low vs. high neutrophil-to-lymphocyte ratio groups: 30 [32.3%] vs. 42 [54.5%], p=0.003), and a higher emergent operation rate (low vs. high neutrophil-to-lymphocyte ratio groups: 5 [5.4%] vs. 20 [26.0%], p<0.001). After one-to-one propensity score matching, the groups comprised 41 patients each; none of the parameters were significantly different between the two groups. The mean follow-up period was 76.3 months. The 5-year overall survival (p=0.637) and disease-free survival (p=0.827) rates were not significantly different between the high and low neutrophil-to-lymphocyte ratio groups.Conclusions: The neutrophil-to-lymphocyte ratio has limited predictive value for determining outcomes in patients with perforated colon cancer.