Early life experiences can influence hypothalamus-pituitary-adrenal (HPA) axis regulation in adulthood, in both animals and humans. In humans, they have also been shown to influence adult attachment styles. However, the relationship between adult attachment styles and HPA axis regulation is largely unexplored. The present study investigated the relationship among varying levels of attachment anxiety and avoidance with both the cortisol response to acute stress (CRS) and the cortisol response to awakening (CRA) in 48 adult women. Attachment-unrelated stress was induced by a laboratory stress task. Saliva for free cortisol assessment was sampled before and after the stress task in the laboratory and at home on 2 consecutive days in the morning after awakening. We found that attachment anxiety but not attachment avoidance was associated with cortisol measures. Attachment anxiety was positively correlated with CRS and negatively with CRA. Finally, the two cortisol parameters were negatively associated with one another. The results are discussed with respect to (1) recent findings suggesting that the HPA system and hippocampus are programmed during critical development periods, establishing a certain trajectory of physiological responsiveness throughout life, and (2) a model that links development of the hippocampus with self development.