This article prospectively explores the effects of collective team work engagement and organizational constraints during military deployment on individual-level psychological outcomes afterwards. Participants were 971 Dutch peacekeepers within 93 teams who were deployed during the end of 2008 and beginning of 2010, for an average of 4 months in the International Security Assistance Force (ISAF). Surveys were administered two months into deployment and 6 months afterwards. Multilevel regression analyses demonstrated that team work engagement during deployment moderated the relation between organizational constraints and post-deployment fatigue symptoms. Team members reported less fatigue symptoms after deployment if they were part of highly engaged teams during deployment, particularly when concerns about organizational constraints during deployment were high. In contrast, the low team work engagement was related to more fatigue symptoms, particularly when concerns about organizational constraints were high. Contrary to expectations, no effects for team work engagement or organizational constraints were found for posttraumatic growth. The present study highlights that investing in team work engagement is important for those working in highly demanding jobs.