International development volunteering is a potential route to returned volunteers' engagement in social action on development issues after placement. Using data from a two-stage qualitative study with returned Voluntary Services Overseas volunteers, and by considering the pre-conditions and motivations for social action, this article shows that although returned volunteers commit to social action, they face challenges to engagement. Motivated by deepened, critical understandings of development, they reject some forms of action, whilst other action they value proves problematic and does not sustain. Barriers include how others respond and the lack of meaningful opportunities provided by organisations at home. Despite these challenges, some returned volunteers develop alternative, sustainable ways of engaging that have greater direct impact on development. This is significant in informing how organisations support returned volunteers (RVs) in taking action.