In order to understand, treat, and prevent acute coronary syndromes we need to improve our ability to identify the rupture-prone, vulnerable atherosclerotic coronary plaque. The diagnostic modalities that are currently available to clinical practice have not fulfilled this expectation, and newer diagnostic techniques based on the recently identified features of the vulnerable plaque are quite promising. Coronary angiography, intravascular ultrasound, and angioscopy have been used in the clinical arena of interventional cardiology with several limitations regarding the identification of the vulnerable plaque. Thermography, optical coherence tomography, elastography, Raman spectroscopy, and infrared spectroscopy are used in clinical trials and the results are encouraging. Ultrafast computed tomography and magnetic resonance imaging have the advantage of being noninvasive. With our progress in the identification of the rupture-prone vulnerable coronary plaque, we will be able to identify patients that are at high risk and will benefit from a more aggressive therapeutic approach.