Ten hemophilic boys participated in a long-term study of psychosocial adaptation and corticosteroid excretion pattern. Methods included inkblot test measurements of body-image boundaries, behavioral ratings, and determinations of urinary 17-OHCS levels. The latter two were performed at home, in a research center, and on a pediatric ward during bleeding episodes. Group mean 17-OHCS level (mg/ 24 hr per square meter) was lowest at home, higher in the research center, and highest on the ward. Each subject tended to hold his relative 17-OHCS level rank within the group in all settings. The well adapted hemophiliacs viewed their body boundaries as definite, and were consistently high 17-OHCS excretors, suggesting relatively high physiologic arousal. The poor adapters were low excretors. The positive correlation between degree of adaptation and adrenal cortical activity was evaluated in terms of types of ego defensive and coping mechanisms and their effectiveness in buffering emotional distress associated with the illness.