Background: This population-based study was to investigate the potential risk factors of cardiotoxicity among colorectal cancer (CRC) patients treated with anticancer drugs. Methods: This was a retrospective cohort study using the National Health Insurance Research Database to identify the CRC patients receiving chemotherapy (CT) alone or CT combined with targeted therapies between 2000 and 2013. The patients enrolled were those who had the first diagnosis of CRC established ≥20 years and had no cancer history three years before the incident diagnosis of CRC. The outcomes of cardiotoxicity were defined by the diagnosis of acute myocarditis, cardiomyopathy, heart failure, hypertensive heart disease, and so on. Results: A total of 11 819 CRC patients were identified and 3781 were eligible; 556 (14.7%) patients developed cardiotoxicity after receiving anticancer treatment. Patients showed a similar risk of having primary outcome (hazard ratio [HR], 0.7; p = 0.3662) between CT and CT combined with targeted therapy groups, whereas the risk of developing secondary outcome was significantly different between the two groups (HR, 0.7; p = 0.0339). The hazard was found to be increased with age (60–69, HR 2.1, p = 0.0236; 70–79, HR 3.3, p = 0.0003; and ≥80, HR 3.7, p < 0.0001). CRC patients who had a prior history of hypertension exhibited a higher risk than those without hypertension (HR 1.6, p < 0.0001). The hazard of having cardiotoxicity among patients with a prior history of severe chronic kidney disease was 2.4 times than that in those without renal dysfunction, regardless of the stage of cancer (HR 2.4, p < 0.0001). Conclusion: CRC patients over 60 years of age run a higher risk of developing cardiotoxicity when treated with anticancer drugs. For CRC patients who have a previous history of hypertension or chronic kidney disease, physicians must be careful in evaluating the risk of anticancer drugs–related cardiotoxicity. Prescribe drugs may prevent cardiotoxicity if necessary.