Recent epidemiologic evidence has pointed to a disproportionate rate of obsessive-compulsive disorder (OCD) among high-combat-exposed Vietnam veterans. This case report describes an individual without previous overt psychopathology who under the stress of combat developed concurrent OCD and posttraumatic stress disorder (PTSD) persisting for more than 20 years. Phenomenologic, behavioral, psychodynamic, and biologic considerations all help to elucidate the potential role of emotional trauma in the pathogenesis of obsessions and compulsions.