Undercover operatives have for decades attempted to interact with and expose criminal activity in identified criminal sub-culture groups of their same ethnic backgrounds, potential criminal participants in diverse ethnic cultural groups other than their own ethnic background, and cross-cultural groups made up of people from different ethnic groups. Through our combined professional experiences (e.g., leadership professor, undercover law enforcement, criminal justice, research, inmate instructor, ethics professors) and having lived and worked in various parts of the world (e.g., Canada, US, UK, Europe, South East and Central Asia) our chapter examines undercover police work and provides a view to cross-cultural issues that exist on both the enforcement and suspect sides of police investigation. A variety of transnational and cross-border ethical issues are examined in undercover work (e.g. trickery, entrapment) along with landmark court cases in an effort to compare and contrast international approaches to undercover operatives. Future directions concerning international collaboration are presented.