Obstructive sleep apnea (OSA) is common among patients with cardiovascular disease; however, the association between OSA and risk of cardiovascular events is not clear. Valham and colleagues studied the effect of OSA on incident stroke, acute myocardial infarction, and death in patients with angina pectoris who were referred for coronary angiography. Patients with OSA were not more likely to die or experience a myocardial infarction than were individuals without OSA, but, after adjusting for potential confounders, patients with OSA were approximately three times more likely to experience a new stroke. Furthermore, there was a dose-response effect, with patients who had mild OSA and those who had severe OSA being 2.4 times and 3.6 times more likely to experience stroke, respectively. While this study contributes to our understanding of the interactions between OSA and the risk of both cardiovascular and cerebrovascular events, it also raises several important questions.