Aims Guidelines on the management of atrial fibrillation (AF) have evolved significantly during the past two decades, but the concurrent developments in real-life management and prognosis of AF are unknown. We assessed trends in the treatment and outcomes of patients with incident AF between 2007 and 2017.Methods and The registry-based nationwide FinACAF (Finnish AntiCoagulation in Atrial Fibrillation) cohort covers all patients with AF results in Finland from all levels of care. We determined the proportion of patients who were treated with oral anticoagulants (OACs) or rhythm control therapies, experienced an ischaemic stroke or bleeding event requiring hospitalization, or died within 1-year follow-up after AF diagnosis. We identified 206909 patients (mean age 72.6 years) with incident AF. During the study period, use of OACs increased from 43.6 to 76.3%, and the increase was most evident in patients with at least moderate stroke risk. One-year mortality decreased from 13.3 to 10.6%, and the ischaemic stroke rate from 5.3 to 2.2%. The prognosis especially improved in patients over 75 years of age. Concurrently, a small increase in major bleeding events was observed. Use of catheter ablation increased continuously over the study period, but use of other rhythm-control therapies decreased after 2013.Conclusion Stroke prevention with OACs in patients with incident AF improved considerably from 2007 to 2017 in Finland. This development was accompanied by decreasing 1-year mortality and the reduction of the ischaemic stroke rate by more than half, particularly among elderly patients, whereas there was only slight increase in severe bleeding events.