We have previously demonstrated lower mean 24-h urinary cortisol excretion in adult offspring of Holocaust survivors with parental posttraumatic stress disorder (and lifetime PTSD), compared to offspring without parental PTSD, and to demographically similar comparison subjects. In the current study, we re-analyze data from our previously published report, plus four new subjects, to further examine the relationship between cortisol and severity of PTSD symptoms in offspring and their parents. We also examine the contribution of current depressive disorder to cortisol levels. Two-way analysis of variance revealed lifetime PTSD to be associated with significantly lower cortisol levels, while depressive disorder was associated with higher cortisol levels. The presence of parental PTSD was associated with lower cortisol excretion in the offspring only if both parents were affected. There were significant negative correlations between severity of parental PTSD and offspring urinary cortisol excretion, and between severity of offspring PTSD symptoms and urinary cortisol levels. The findings amplify our earlier descriptions of children of Holocaust survivors with PTSD as a sample 'at risk' for PTSD by demonstrating relationships between lowered cortisol excretion in these offspring and their experience of their parents' PTSD symptoms.