In patients with ongoing angina, despite optimal medical therapy, the best therapeutic alternative is coronary angiography followed by emergency coronary revascularization with surgery or angioplasty. However, whether or not all patients should have early angiography and revascularization is a matter of debate. This paper reviews the advantages of modern medical therapy in this setting and the problems associated with early coronary revascularization. In particular, it analyses the data from the main clinical trials that have specifically compared an early invasive procedure with a conservative strategy in unstable coronary syndromes. Finally, it assesses the impact of the new antithrombotic agents, such as glycoprotein IIb/IIIa receptor blockers, particularly during coronary percutaneous interventions. The data reviewed suggest that early invasive intervention should be reconsidered, and that patients should be controlled (if possible) under medical treatment until non invasive stratification tests allow the identification of those patients who would benefit most from revascularization.