This article reviews the literature on health surveillance conducted during military deployments, focusing on models for assessing the impact of operational deployments on peacekeepers. A discussion of the stressors and potential mental health consequences of peacekeeping operations follows with relevant examples of findings from U.S. and international military forces. Psychological screening in different peacekeeping operations conducted in U.S. Army-Europe is reviewed. The review begins with the redeployment screening of military personnel deployed to Bosnia mandated under the Joint Medical Surveillance Program, and continues through the present screening of units deployed to Kosovo. The detailed description of the screening program includes a discussion of procedures and measures and demonstrates the evolution of the program. A summary of key findings from the screening program and a discussion of future research directions are provided.