This article analyses the role of the European Union (EU) in collaboration with the East African Community (EAC) in responding to challenges of policing against cross-border crime along the Tanzanian–Kenyan border. It assumes and argues that the EU’s capability as well as presence in regard to peace and security have a significant impact on addressing those challenges. The article intends to refer to the concept of interregionalism in order to describe and explain the nature of the EU–EAC relationship. The literature review and field data indicate several challenges faced by police forces in law enforcement related to the porous border between Tanzania and Kenya. The article highlights how these challenges have been hindering crime- combating efforts across the borders. The conclusion reached is that cross-border crime control calls for improved cooperation between concerned states as well as with external actors such as the EU.