Acute coronary ischemia results from pathophysiological processes that include coronary atherosclerosis, plaque rupture, and coronary thrombosis. Unstable angina is the most common acute coronary syndrome. However, its diagnosis may be unclear initially, and even in patients who are eventually shown to have this diagnosis, risk can vary widely. In addition, a diverse array of investigations and therapeutic options is available. These facts underline the importance of accurate risk stratification, with the aim of appropriate management, whether medical therapies or, in addition, early invasive investigation and possibly revascularization. In this article, early risk stratification, the impact of measurement of troponins, the appropriate timing of coronary angiography, and role of medical therapies, particularly newer pharmacological classes—glycoprotein IIb/IIIa inhibitors and low-molecular- weight heparins—are discussed...