Short sleep duration has a substantial influence on the overall health of an individual. Short sleep time can be a consequence of lifestyle habits, environmental factors, or the presence of a sleep disorder, such as insomnia or sleep-disordered breathing. Short sleep time is associated with increased morbidity and mortality, mainly from cardiovascular disorders (including coronary artery disease, arrhythmias, and hypertension). Several biological mechanisms have been proposed as a possible link between short sleep duration and these diseases, such as involvement of the autonomic nervous system, endothelial function, metabolic regulation, inflammation, and the coagulation system. In this Review, we provide an overview on the effects of short sleep duration on cardiovascular health and diseases and discuss the main pathophysiological mechanisms involved, taking into account both experimental data and clinical evidence.