Forensic DNA technology and DNA databases are among the two most effective and efficient crime fighting tools law enforcement employs. The author argues that the single most important aspect to the effective use of DNA databases is the legislation governing its use. The European Union recently recommended that member nations develop compatible DNA databases because of their recognized importance as an effective cross-border crime fighting system. The paper presents summaries of international and European countries that either have or are in the process of implementing DNA databases and then offers data on the databases’ effectiveness. Next, critical issues important to consider when developing DNA legislation are presented and include questions such as which offenders should be included in the database and when DNA profiles should be removed. The paper reviews the type of DNA database systems being implemented in each different country and presents the type of information included in the DNA profiles. Finally, examples of United States and New Zealand database legislation are presented for comparison purposes. Notes, author biography