The practice guideline 'Atrial fibrillation' from the Dutch College of General Practitioners provides the general practitioner with guidelines for the diagnosis and management of patients with atrial fibrillation. Atrial fibrillation can be detected by observation of the cardiac rhythm during every measurement of the blood pressure. The diagnosis 'atrial fibrillation' must be made on the basis of an ECG. Atrial fibrillation must not be looked upon as an isolated phenomenon: possible comorbidity (cerebral infarction ('transient ischaemic attack'; TIA), hypertension, diabetes mellitus, heart failure, coronary heart disease, hyperthyroidism) should be taken into consideration in the evaluation. Particular attention should be given to determining whether heart failure is also present. An important goal of treatment is the prevention of thromboembolic complications. Cardioversion is not generally recommended. The symptoms may be an indication that an attempt should be made to restore sinus rhythm. This constitutes one of the indications for referral for specialised treatment.