Validation Studies ; Journal Article ; Hospitals are major providers of health services and analysis of hospital activity data is of great interest for both policy makers and public health researchers. The WHO Regional Office for Europe disseminates the hospital discharge data from European countries through the European Hospital Morbidity Database, available on http://data.euro.who.int/hmdb. In order to ensure that reliable high quality data on hospital activities can be published in a timely manner, a program for validation of hospital discharge data has been developed using the R language for statistical computing. This program has been in use since the October 2012 version of the European Hospital Morbidity Database and its use has contributed to improved quality and comparability of data on hospital activities across Europe.