We attempted to determine the incidence, timing and correlates of very early (< 24 hours) major adverse clinical events in patients undergoing contemporary percutaneous coronary intervention (PCI). Early discharge following PCI may offer significant advantages to patient and practitioner, but the timing of, and risk factors for, very early (< 24 hours) major adverse clinical events following PCI are not well characterized. A retrospective analysis of the CREDO trial was performed. A total of 1,815 patients underwent a PCI procedure and 139 patients (7.7%) experienced a major adverse clinical event (death, myocardial infarction or urgent target vessel revascularization) within the first 28 days. The majority of these events (111 patients) occurred within the first 24 hours, with the greatest risk of an event within the first 6 hours. Multivariable predictors of very early events were age, AHA lesion grade, history of peripheral vascular disease, preprocedural TIMI flow grade and no. of vessels with stenosis > 50%. These data show a very low and constant risk of adverse events 6 hours following PCI.