Objective: Atherosclerotic heart diseases are less frequently seen in patients with Gilbert’s syndrome (GS). We aimed to investigate whether serum adiponectin (APN) and epicardial adipose tissue (EAT) thickness have an effect beside the antioxidant effect of bilirubin in lowering the incidence of the atherosclerotic process. Methods: Sixty-eight patients diagnosed with GS (39 females and 29 males) who had applied at the internal medicine clinic of the hospital were included in this cross-sectional, observational study. The control group included 63 healthy people (39 females and 24 males). EAT thickness was measured by echocardiography. The serum APN levels were also checked. Statistical analysis was performed by using independent sample t-test, Pearson correlation and linear regression analyses. Results: The mean age of the GS group was 28±9 years, and the average EAT thickness was found to be 2.5±0.1 mm. The mean age of the control group was 26±6 years, and the average EAT thickness was found to be 4.2±0.5 mm. When comparing the two groups, the EAT thickness of the GS group was found to be significantly lower (p<0.001) than that of the control group. In the GS group the APN was 14.9±4.2 mg/L, and in the control group the APN was 12.6±4.5 mg/L (p<0.022). We found that total bilirubin (β=-1,607, p<0,001) and indirect bilirubin (β=1,086, p<0,001) have an independent association with decreased EAT thickness. Conclusion: EAT thickness is associated with coronary atherosclerosis. Low EAT thickness may be related with low release of proinflammatory cytokine. High levels of APN may be related high anti-inflammatory effect. Therefore, low EAT thickness and high levels of APN may demonstrate protective effect on atherosclerotic heart diseases in GS patients.