Combating trafficking in human beings (THB) for labor exploitation requires additional skills, knowledge, and awareness for effective investigation and prosecution, and for the identification and assistance of victims of this form of THB. Actors other than the police and the prosecution services (such as labor inspectorates, social investigation services, and municipalities) have also become involved in these activities. It is unclear which role these actors can have in identifying victims and in investigating and prosecuting (cross-border) THB for labor exploitation and which improvements are needed. They are often unfamiliar with, for instance, the specific needs of victims, how trafficking networks operate, and how to cooperate with colleagues abroad. These problems obviously hamper the combating of THB for labor exploitation. In addition, difficulties in defining THB for labor exploitation still exist. Labor exploitation, as such, is not a term used in the Palermo Protocol or the EU Directive on Preventing and Combating THB and Protecting Victims. One can say that labor exploitation includes, at least, forced and compulsory labor and services, slavery, and slavery-like practices, although this does not solve the problems encountered in defining the crime. In this book, these and other problems, as well as the challenges of dealing with these problems, are identified. It includes research in five countries (Austria, The Netherlands, Romania, Serbia, and Spain), research on the EU legal framework, an analysis of the country studies, as well as four articles reflecting on these problems.