Abstract: Objective：To explore the prevalence of malignant tumors in patients with coronary artery diseases in a single clinical center. Methods：A total of 20 191 patients underwent coronary angiography were selected from January 2016 to December 2017 in Zhongshan Hospital, Fudan University. Coronary artery diseases and the prevalence of concurrent malignant tumors were studied using medical history system. Results：A total of 18 500 patients were definitely diagnosed with coronary artery lesions by their medical history of coronary artery revascularization or angiography. Their mean age was (64.2 ± 9.8) years old. Among these patients, 391 had malignant tumors (2.1%). Among the 391 patients, the top five malignant tumors were urological and male reproductive system malignant tumors, colorectal cancer, lung cancer, gastroesophageal malignant tumors and breast cancer, with respective percentages of 18.9%, 17.1%, 14.1%, 13.6%, and 11.0%. Conclusions：Coronary artery diseases complicated with malignant tumors are not unusual in clinical practice. It is urgent to strengthen the clinical cooperation of multidisciplinary diagnosis and treatment on cardio-oncology.