Sleep apnea is awidespread and yet still underdiagnosed condition. Various studies from the past have provided evidence that there is alink between sleep apnea and various cardiovascular diseases, including arrhythmias. The aim of this article is to provide an overview of the current study situation and to point out possible consequences relevant to everyday life. Asystematic search was carried out in various databases using the keywords sleep apnea (OSAS/SA) and arrhythmias/dysrhythmias. There are several pathophysiological links between sleep-related breathing disorders and cardiac arrhythmias, the most important of which appear to be intrathoracic pressure, increased adrenergic tone as well as recurrent hypoxia and hypercapnia. This results in an increased occurrence of clinically relevant arrhythmias, such as atrial fibrillation, symptomatic bradycardia, high-grade atrioventricular (AV) blocks as well as ventricular arrhythmias in patients with untreated sleep apnea. These pathologies also appear to be positively influenced by the treatment of sleep apnea. Aclose correlation between sleep apnea and cardiac arrhythmias is undisputed. Large randomized studies in this respect are so far rare but it is undisputed that a thorough search should be carried out for sleep apnea and consistently treated in patients with ahistory of cardiac disease as this can have arelevant influence on the treatment and ultimately the prognosis of the patient.