 I'm very pleased to introduce the IOM Handbook on protection and assistance for migrants' vulnerable to violence, exploitation, and abuse. This handbook was developed within the global action against trafficking in persons and smuggling of migrants, a program funded by the European Union and implemented by UNODC in partnership with IOM and USF. The handbook's development was prompted by growing concern about the protection risks faced by migrants. Sadly, migrants face numerous forms of violence, exploitation, and abuse, including trafficking in persons, labor exploitation, and sexual violence. It has become increasingly clear over the past few years that greater efforts are needed to understand the dynamics underpinning migrant vulnerability, along with greater efforts to protect and assist the migrants affected. This handbook responds to this need by providing a structured approach to understanding migrant vulnerability by analyzing risk and protective factors at the individual, household, community, and structural levels. It includes guidance on how to conduct research on these matters to inform evidence-based policy, but also on how to analyze how these dynamic affect individual migrants and how to best respond to the protection and assistance needs of vulnerable migrants and their families. The handbook also aims to support comprehensive and coordinated responses. Violence, exploitation, and abusive migrants is the result of a broad range of factors, including social, political, and economic factors, which require investment in action by an equally broad range of actors. It is our hope that all actors concerned with migrant protection will find this handbook a valuable resource, and that vulnerable migrants themselves will benefit from its implementation.