Most research on domestic violence perpetrator programs has been carried out in North America. It does not yet provide a clear picture on what works with these offenders and cannot be generalized to other cultural and legal systems. Therefore, in Part I of this article, we present the results of a survey of 54 programs that were in place in 19 European countries that addressed the programs’ practice and effects. The survey captured data about program design, delivery, administration, infrastructure, and other features. Most programs applied cognitive-behavioral, profeminist, or psychodynamic treatment, or a combination of multiple treatment types. There was a wide disparity in approaches to handling domestic violence perpetrators, and a particular dearth of high-quality evaluation throughout the continent. Possible explanations for this disparity and avenues for improvement are discussed, related to a systematic review of European outcome evaluations (Part II).