Does UN peacekeeping reduce the number of people forcibly displaced by violence? While previous research has found that the presence and size of peacekeeping deployments can reduce violence, little is known about how peacekeepers affect other aspects of civilian protection. Using original data on sub-national events of forced displacement and the location and size of UN troop deployments this study systematically evaluates the criticized efforts of UNMISS in South Sudan, while simultaneously testing hypotheses on peacekeepers and forced displacement. It is hypothesized that increasing numbers of troops affect the flight equation among civilians through the promise of and actual deterrence of violence. These deterrence-based hypotheses are also discussed in relation to the South Sudan context, creating scope conditions for their possible application in this case. The statistical analysis provides, however, no robust evidence for peacekeepers reducing the occurrence or levels of forced displacement, and only weak evidence of displaced congregating in larger numbers around peacekeeping locations. The paper ends by arguing that the theoretical argument provided may still be valid, but that an effect was not feasible to identify in South Sudan where the peacekeeping mission – despite its comparatively large numbers – lacks credible deterrent capacity.