The paper aims primarily on the specification of the concept of "alternatives to detention” itself and its definition in EU law. Despite the growing interest of States on the implementation of legal provisions for the alternatives to detention, there is no uniform legal definitions of the concept of "alternatives to detention" and, consequently, different approaches to the application of the concept in practice occurs. Thus, the specification of the existing legal definitions of the concept is necessary for a better understanding of the alternatives to administrative detention in the framework of the EU law. Following the clarification of the concept, the paper approaches the EU legal rules in force, in particular the a EU directive 2013/33/EU laying down standards for the reception of applicants for international protection (Reception Conditions Directive) and Directive 2008/115/EC of the European Parliament and of theCouncil on common standards and procedures in Member States for returning illegally staying third-country nationals (Return Directive). In this connection the paper presents and cha characterizes briefly the existing alternatives to detention as laid downin the national laws and applied by the EU Member States