Objective To explore the value of CT coronary angiography in the preoperative coronary heart disease (CAD) screening in the rheumatic left atrioventricular valve lesions. Methods 42 cases of patients with rheumatic left atrioventricular valve lesions were selected for the study, and they were treated with 500-row CT coronary angiography and then selective coronary angiogram before valve surgery. The sensibility, specificity, positive or negative predictive value (PPV or NPV), and accuracy of coronary angiography for the diagnosis of CAD were evaluated in segmental, vascular and patient levels by contrast with coronary angiogram results. And the Kappa values were used to evaluate the consistency of coronary angiography and coronary angiogram in the diagnosis of CAD. Results The sensibility, specificity, PPV and NPV levels of CT in the diagnosis of CAD on segmental level were 90.63%, 99.01%, 85.29% and 99.40% respectively, and the four indexes in the the diagnosis on vascular level were 80%, 92.19%, 76.19% and 93.65%, and the four indexes in the diagnosis on patients level were 80%, 92.59%, 85.71% and 89.29% respectively. After comparsion with coronary angiogram, the accuracy rates of the 500-row CT coronary angiography in the segmental, vascular and patients levels were 98.51%, 89.29% and 88.10%, and the Kappa values were 0.871, 0.710 and 0.737 respectively. Conclusion CT coronary angiography can have a high accuracy rate in checking coronary heart disease, and can be used in the preoperative coronary heart disease screening in the rheumatic left atrioventricular valve lesions.