Background: Many evidence has documented that the development of coronary artery disease involves lipid oxidation and formation of oxygen radicals as atherosclerosis and inflammation are associated with formation of oxygen and peroxyl radicals. Bilirubin has proven to be a potent antioxidant under physiological conditions by inhibiting both lipid and protein oxidation. Objective: This study was aimed to show the relationship between serum total bilirubin and different types of acute coronary syndromes (STEMI, Non-STEMI, unstable angina) in patients admitted at Coronary Care Unit, Sohag University Hospital. Patients and methods: This cross-sectional study included a total of 100 patients, 64 of them were men presented with acute coronary syndrome, admitted at Coronary Care Unit, Sohag University Hospital. This study was conducted between January 2020 to June 2020. Results: The mean age was 55.4 years; 64 (64%) were males, 44 (44%) were current smokers, 37 (37%) were HTN, 39 (39%) were DM, 71 (71%) had family history of IHD, 17 (17%) were obese.  When the patients were divided into 3 groups (group A, n = 28 "28%", group B, n = 13 "13%", and group C, n = 59 "59%"). Serum total bilirubin was significantly different (group A; Mean ± SD = 0.627 ± 0.241), (group B; Mean ± SD = 0.527 ± 0.173), (group C; Mean ± SD = 0.795 ± 0.367). "P-value = 0.007; highly significant". Conclusions: It could be concluded that there is an inverse relation of bilirubin with acute coronary syndromes (ACS). These strengths the fact that bilirubin acts as an antioxidant and has cardioprotective action and patients with ACS have lower levels of bilirubin.