Socioeconomic disadvantage during childhood and adolescence predicts poor mental and physical health and premature death by major medical diseases in adulthood. However, the neural pathways through which socioeconomic factors may exert a developmental influence on health and longevity remain largely unknown. This fMRI study provides novel evidence of a unique relationship between the perception that one's parents had a relatively low social standing--a putative indicator of early socioeconomic disadvantage--and greater amygdala reactivity to threatening facial expressions. This relationship was not explained by several possible confounders, including sex, ethnicity, dispositional emotionality, symptoms of depression and anxiety, parental education and participants' perceptions of their own social standing. The amygdala expresses marked developmental plasticity and plays instrumental roles in processing emotional information, regulating emotion-related behaviors and orchestrating biobehavioral stress responses throughout life. Thus, these findings may provide insight into the neurodevelopmental pathways impacting socioeconomic disparities in health.