Diabetes is an independent risk factor for atrial fibrillation (AF). Frequently, it is part of the metabolic syndrome cluster, which includes obesity and hypertension that are independently associated with AF. The risk appears to be higher with longer duration of diabetes and inadequate glycemic control. Patients with diabetes and AF have a substantially increased risk of death and serious cardiovascular complications compared with those in sinus rhythm. Conversely, good metabolic control appears to be associated with maintenance of rhythm after successful therapeutic conversion to sinus rhythm by catheter ablation or electrical cardioconversion of AF. AF puts patients with type 2 diabetes at a high risk of cardiovascular complications and death, which could be successfully addressed by new classes of antidiabetic agents such as incretin analogues or sglt-2 inhibitors. Thus, a diagnostic strategy that addresses the increased risk for AF is urgently recommended, in addition to diabetes monitoring in routine outpatient practice. In order to prevent thromboembolic complications, which frequently determine the prognosis for this patient population, appropriate anticoagulation remains the mainstay of therapy, whereas the prognostic value of reinstalling sinus rhythm awaits further evidence.