Alternative Dispute Resolution (ADR) is meant to resolve conflicts, avoiding long and expensive court trials. This kind of dispute resolution method has recently gained a great deal of importance in the area of private international relations. In particular, Mediation, considered an effective and well known way to settle disputes in Anglo-American countries such as the U.S., has recently earned greater relevance within European Union countries, thanks to Directive 2008/52CE on Transnational Mediation in civil and commercial matters. This Directive has been enacted in Spain via Law 5/2012 regulating, inter alia, Mediation in non-international cases. The present work addresses cross-border civil and commercial mediation under this Spanish Law, analyzing the importance of quality education for international mediators in this area, the agreement to mediate and provide mediation services in international cases, the process of mediation itself, and the particular characteristics of the agreement to resolve private international controversies.