The interrelation between arrhythmias and lifestyle factors is acknowledged. On the one side, there is a recognized interaction between atrial fibrillation and obesity, hypertension, dyslipidemia and type 2 diabetes mellitus. Saturated fats, excessive added salt, tea, coffee and energy drinks are often deleterious in rhythm disorders. The role of others, such as cocoa-rich foods, is less evident: several authors displayed the beneficial effect of the polyphenols content on numerous cardiovascular risk factors, while little is known about the potential link between diet and incident arrhythmias. Arrhythmias’ most frequent risk factors include aging, hypertension, congenital cardiopathy, heart failure, valvulopathy, thyroid diseases and diabetes. Nevertheless numerous arrhythmias are not related to any of these risk factors: in these cases, immunological, functional and even nutritional mechanisms might be involved in dysrhythmias’ genesis. Aim of this narrative review is to analyze the potential adverse effect of cocoa excessive consumption on cardiac rhythm and its mechanisms and to provide state-of-the-art knowledge on this topic.