This paper deals with the validation of the information stored in the Netherlands central pacemaker patient database. At this moment the registry database contains information on more than 70500 patients, 85000 pacemakers and 90000 leads. The validation procedures consisted of an internal consistency check and comparison with different hospital and pacemaker company databases. Although comparison of the exact information resulted in a meager agreement, the relevant information, based on the purpose of the database, proved to have the same accuracy as other registries. A number of suggestions to enhance the accuracy of this nationwide functioning database is mentioned.