This research examined romantic partners’ stress reactivity to relationship conflict through the lens of a threat vs. challenge perspective. We assessed the DHEA-S to cortisol ratio (anabolic balance) as an index of 330 newlywed partners’ threat or challenge orientations to a conflict discussion with their spouse and then examined whether these orientations were predicted by their attachment styles. Consistent with predictions, anxious attachment predicted lower anabolic balance trajectories, compared to secure attachment. Results were decomposed into DHEA-S and cortisol components. DHEA-S levels were found to be more congruent with challenge, while cortisol levels were more congruent with threat.