Cardiovascular disease has emerged as the leading cause of mortality worldwide. Acute coronary syndromes occur as a result of thrombotic complications at the site of atherosclerotic plaques, often following rupture of the fibrous cap of vulnerable plaques. A growing body of evidence from clinical and experimental studies suggests that acute respiratory tract infections can act as a trigger for acute coronary syndromes. The mechanism underlying this association has yet to be established. We explore the mechanistic links between acute respiratory tract infection and acute coronary syndromes, with a particular focus on the host response to infection and its potential interaction with pathogenic processes involved in atherosclerosis and atherosclerotic plaque rupture. The prothrombotic and haemodynamic effects of acute respiratory infection are also discussed. We review mechanistic studies as well as clinical trial data to investigate potential links between acute coronary syndromes and acute respiratory infection. Understanding the link between acute respiratory infections and acute coronary syndromes should help improve the outcome of acute coronary syndromes.