PURPOSE: Previous studies have revealed that predictors and risk factors of pulmonary thromboembolism (PTE) are malignancy, immobilization, diabetes, and obesity in the postoperative patients. However, in patients undergoing colorectal cancer, studies of PTE have not been enough. Thus, we investigated the risk factors of PTE related to colorectal surgery. METHODS: From January 2009 to October 2014, 312 patients received colorectal surgery without other organ resection. The postoperative patients with PTE were 14 (4.5%), and they were classified by sex, age, and stage as a 1:3 paired match to the control group. A multiple logistic regression was performed to identify which factors were associated with PTE. RESULTS: One patient was in stage I, 3 in stage II, 9 in stage III, and 1 in stage IV. In the binary logistic regression analysis, history of diabetes mellitus (odds ratio, 6.498; P = 0.031) and being overweight (odds ratio, 10.018; P = 0.014) were independent risk factors for PTE in patients undergoing colorectal cancer. CONCLUSION: A history of diabetes mellitus and being overweight were independent risk factors of PTE after colorectal cancer.