Both coping behaviors and physiological vulnerability to stress have been found to be associated with the development of psychopathology; however, less is known about the interrelations between coping and physiological stress responses. This study explored relations between late adolescents' styles of coping with distress and their physiological reactivity and recovery to negotiating conflict with their romantic partners. Partners' coping styles and the interaction between partners' coping styles were also examined as predictors of stress responses. One hundred and ninety couples were asked to discuss and attempt to resolve a conflictual issue that they had disagreed about in the previous month. Physiological reactivity was assessed using samples of salivary cortisol, a primary hormonal product of one of the major stress response systems. A salivary cortisol sample at entry, a pre-task anticipatory sample, and 5 post-task samples were collected. Growth modeling of the cortisol data indicated that dyadic coping was a better predictor of cortisol reactivity and recovery during relationship conflict than individual coping behaviors alone. In addition, relations among coping and physiological stress responses were found to be significantly different for males and females.