Although clinical trial results and the implementation of current guidelines appear to have encouraged progress in the treatment of arrhythmias, great discrepancies still exist between European Society of Cardiology (ESC) member countries. Guidelines are not adhered to for a variety of reasons. This cannot be explained only by economic factors, although these obviously play a substantial role. Other factors responsible for adequate guideline implementation appear to be the lack of trained personnel, the lack of infrastructure, or different health insurance systems. In this complex scenario, the data based on European registries are useful for creating standards and harmonizing the treatment of arrhythmias. Moreover, a summary of registry data, such as presented in the European Heart Rhythm Association (EHRA) White Book, can provide the opportunity to share and exchange information among ESC member countries on specific needs for improvements, reimbursement policy, and training issues.