Cluster of differentiation 40 ligand (CD4OL) is a member of tumor necrosis factor super family. The data available so far shows that CD4OL has important role in the development of atherosclerosis and progression of acute coronary syndrome (AC S).This work aimed at studying the level of soluble CD4OL in patients with coronary heart disease i.e. stable angina, unstable angina and acute myocardial infarction. This study revealed that sCD4OL is increased in ACS (unstable angina and myocardial infraction) much more than stable angina and control although it was not clarified if it is a cause or a consequence.Elevated sCD4O ligand is not related to age, sex, family history, or degree of myocardial necrosis as detected by enzymatic criteria. This should incite future studies of sCD4OL lowering therapy in coronary artery disease.