Epicardial adipose tissue (EAT) may play an important role for developing an unfavorable cardiovascular risk profile. However, it has not been investigated if EAT is associated with coronary atherosclerosis in non-obese patients. We aimed to evaluate whether EAT is related to coronary atherosclerosis in non-obese patients. Among the consecutive patients who underwent coronary CT angiography (CCTA) with an intermediate pretest likelihood for having coronary artery disease, we excluded the patients whose body mass index (BMI) was over 30 kg/m² or whose CCTA image quality was not sufficient for the detection of coronary plaque. The remaining patients were divided into the normal and abnormal groups based on the presence of atherosclerotic plaques as seen on the CCTA images. The cardiovascular risk factors were matched between the two groups. Ultimately, 100 patients were included in the normal group and 100 patients were included in the abnormal group. The pericardial fat area was measured at the subaortic level of the heart on the axial CT images. The pericardial fat area was significantly larger in the abnormal group as compared to the normal group (18.1 ± 10.2 vs. 14.6 ± 8.7 cm², P = 0.019). Even though the overweight patients (25 ≤ BMI < 30) were excluded, the pericardial fat area was still significantly larger in the patients with coronary atherosclerotic plaque as compared to that of the patients without coronary atherosclerotic plaque (18.7 ± 11.5 vs. 13.2 ± 7.9 cm², P = 0.006). Pericardial fat was more abundant in the non-obese patients with coronary atherosclerosis as compared to that of the patients without coronary atherosclerosis, after controlling for the other cardiovascular risk factors.