Background: In resected CLM, randomized studies of Ox CT have not demonstrated improvements in overall survival (OS) and Ox CT has not been compared to non-Ox CT. The aim of this study was to assess the impact of Ox CT regimens on OS in patients that have undergone resection of CLM in a real world setting. Methods: Patients who underwent resection of CLM in the provinces of Alberta and British Columbia, Canada were identified from 1996-2016. Perioperative (pre and/or post) CT regimens were reviewed and categorized as Ox CT, non-Ox CT or no CT. OS was measured from the time of metastatic diagnosis to death or last follow-up using the Kaplan-Meier method. CT regimens were compared using the log-rank test and a Cox regression model, adjusting for possible confounders including age, gender, primary tumor sidedness and the presence of synchronous metastatic disease. Results: 516 patients were identified who underwent R0 resection of CLM for mCRC, including 205 that received Ox CT, 129 non-Ox CT and 182 with no CT. Of these patients, 24% and 56% received pre-operative and post-operative CT, respectively. 70% of these patients received a fluoropyrimidine (5-FU or capecitabine), 40% oxaliplatin, 13% irinotecan, 7% received bevacizumab and 1% panitumumab. Median age of these patients was 64, with 60% male and 57% demonstrating synchronous metastatic disease and 38% right-sided primary. The median OS for patients receiving Ox CT was 98 months, for non-Ox CT 60 months and no CT 56 months, p = 0.01. After adjusting for potential confounders with a Cox-proportional hazard model, patients who received Ox CT had a lower risk of death HR of 0.65 (95% CI 0.48-0.87, p < 0.01), while the non-OX CT group did not, HR 0.84 (95% CI 0.62-1.13, p = 0.25) compared to no CT. Conclusions: Perioperative Ox CT appears to improve OS in conjunction with R0 resection of CLM in this multicenter population based study. This observation remained significant even after controlling for potential confounders. Ox CT should be considered in patients that undergo R0 resection of CLM, in favor of non-Ox CT. The addition of biologic agents to CT remains limited. Further studies should evaluate the optimal timing and duration of perioperative CT.