The current study is a review of existing literature on perceived threat across childhood (0–19 years). There is strong evidence from this body of research that threat detection emerges in infancy and is present throughout childhood, with meaningful links to child adjustment. The wide range of methodologies employed to assess threat include biological measures (event-related potential and functional magnetic resonance imaging), observational data (gaze duration and response time), and a range of ways of gathering cognitive data (threat appraisal). Across methodologies, a uniform finding is that children who have higher threat attenuation are at increased risk for the development of anxiety disorders. It also seems that children’s attention to threatening stimuli may vary across development, with heightened attention in infancy and early childhood. These findings have meaningful extensions for children who are living in violent families. Since many children living in violent homes are exposed to the threat of violence beginning in infancy, these children may be at heightened risk as compared to their nonexposed peers for the development of maladaptive patterns of threat detection and response. There is some evidence that this long-standing pattern of vigilance toward threat in key developmental periods may in part explain the increased risk of the development of anxiety disorders and posttraumatic stress disorder following exposure to violence.