BACKGROUND: The Register for Suicide Attempts (RSA) is a product of the WHO research project "WHO/Euro Multicentre Study on Parasuicide", which, among other things, had the purpose of collecting data on suicide attempts from 13 European countries. Data is collected in order to calculate trends and identify high-risk groups. Data collection for the RSA started in 1989. METHODS: The RSA is a longitudinal, person-based register. It contains information about people who have been in contact with the health care system in the County of Funen as a result of a suicide. The RSA contains 11 variables, which describe the incident in detail, and a number of variables describing the person. The RSA contains data covering the period April 1989 to December 2001 and is updated annually. Data is collected from somatic and psychiatric hospitals in an administrative district (County of Funen). The data collection is done manually by going through all the records in which a contact to the health care system, i.e. a potential suicide attempt, is described. Only incidents matching the WHO definition of an attempted suicide are registered. CONCLUSION: Data from the RSA has been used in national and international studies. The RSA is the most suitable register in Denmark for analyses of suicide attempts.