Background: Attachment style has been linked with basal cortisol secretion in healthy adult women. We investigated whether dysregulation in basal cortisol secretion may be evident in younger healthy females. Methods: Sixty healthy females aged 9-18 years (mean 14.16, SD [plus or minus] 2.63 years) participated in the Attachment Style Interview (ASI). Eight saliva samples, synchronised to awakening, were collected per day on two consecutive weekdays to examine the cortisol awakening response (CAR) and the subsequent diurnal decline. Results: Participants exhibiting an anxious attachment style had higher cortisol levels on awakening, in contrast to those who were securely attached. The anxious insecure group also showed an attenuated CAR compared to all other participants. Attachment style groups did not differ in cortisol secretion over the remainder of the day. Conclusions: These findings indicate that the same pattern of cortisol dysregulation associated with disorder in adulthood manifests as a function of anxious (but not avoidant) insecure attachment style in females during healthy childhood and adolescence.