Growing up in an adverse early environment is related to a number of negative health outcomes later in life, and dysregulation of the HPA axis may serve as the means by which this process occurs (Repetti et al., 2002). Indeed, early environment has been linked to altered physiological responses to general stressors in adulthood, but it remains unclear whether physiological responses to marital stress are also affected. Thus, the present work addresses two central questions in 129 newlywed couples: (1) How does growing up in an adverse early environment relate to physiological stress responses (assessed by cortisol) to a relationship conflict? (2) Does having a supportive spouse moderate this relation? The results provide some support for the link between early environment and cortisol reactivity among husbands, and marginal support for the moderating role of spousal support.