The International Organization for Migration (IOM) is a key provider of Assisted Voluntary Return (AVR) programmes. This chapter examines the concept of ‘voluntariness’ in the context of AVR, by tracing the evolution of its articulation in key IOM policy documents and comparing it with the concept in other legal domains including: the law on human trafficking (where abuse of vulnerability is sufficient means for consent to be deemed ‘irrelevant’) and contract law. The chapter assesses how the conceptualization and limits on voluntariness in these other fields is relevant to the interpretation of IOM’s legal obligations, and in turn assesses the legality and appropriateness of IOM’s role in AVR. The view of IOM as a blind implementor of States’ wishes in the context of AVR programming is problematized in light of its legal obligations as an international organisation. The responsibility of States for their involvement in IOM’s AVR activities (including funding) is also analysed. Finally, the chapter concludes that the decision to return must be understood as a process rather than a one-off pronouncement and makes a number of recommendations for reform of the organisation’s practices.