In the current study we tested whether ADRA2B moderates stress regulation of Holocaust survivors as indexed by their diurnal cortisol secretion and cortisol reactivity to a stressor. Salivary cortisol levels of 54 female Holocaust survivors and participants in the comparison group were assessed during a routine day and in response to a stress-evoking procedure (an adapted version of the Trier Social Stress Test [TSST]). ADRA2B did not moderate differences between Holocaust survivors and participants in the comparison group in terms of cortisol reactivity to the TSST. Holocaust survivors with the wildtype ADRA2B, however, displayed higher diurnal cortisol levels than did participants in the comparison group with the same genotype, whereas no difference was found between these groups in carriers of the deletion variant, previously associated with more reexperiencing of traumatic events. Carriers of the deletion variant might have been driven in the long run to resolve their vividly remembered experiences, and therefore currently show less stress dysregulation as evident from their cortisol levels.