Acute coronary syndromes represent the most severe consequences of atherosclerosis, most often triggered by the rupture of a coronary plaque, which, for various reasons, has become unstable. In many cases, these rupture-prone vulnerable plaques are difficult to diagnose, because they do not always cause significant obstruction noticeable by coronary angiogra- phy. Therefore, new methods and tools for the identification of vulnerable plaques have been proposed, many of which are currently under study. Various biomarkers have been suggested as predictors of a vulnerable plaque, as well as indicators of an increased inflammatory sta- tus associated with higher patient susceptibility for plaque rupture. Integration of such bio- markers into multiple biomarker platforms has been suggested to identify superior diagnos- tic algorithms for the early detection of the high-risk condition associated with an unstable plaque. The aim of this review is to summarize recent research related to biomarkers used for the early detection of vulnerable plaques and vulnerable patients.