Abstract Post-traumatic stress disorder (PTSD) is a mental health disorder precipitated by a stressful event that produces fear or terror in the individual. Post-traumatic stress disorder studies, particularly in early sexual abuse, have been associated with neuroendocrine dysfunction, most notably the hypothalamic–pituitary–adrenal (HPA) axis. Since the literature on PTSD and neuroendocrine factors in young subjects has been sparse, the present studies were designed to look at the basal functioning of the HPA axis in response to early sexual abuse in girls aged 5 to 7 years. Morning salivary samples were collected for cortisol determination from subjects and controls who were scheduled for a physical exam by their pediatrician. The present study shows that subjects who had been abused within the last couple of months had significantly lower cortisol in comparison to control subjects (age, social economic status and race matched). The data suggest that children may have an impaired HPA axis after early trauma.