Cardiovascular reactivity (CVR) has been identified as a potential mechanism linking a variety of psychosocial processes to the development of cardiovascular disease. Although the effects of hostile and supportive social stimuli on CVR have been studied extensively, less is known about the effects of a second major dimension of social relations--dominance versus submissiveness. In the present study, 45 married couples participated in an interaction task involving the assertion of differing opinions. Subjects also provided ratings of their typical level of dominance versus submissiveness in relation to their spouse. Consistent with predictions derived from related conceptual models of psychological determinants of CVR, blood pressure reactivity was positively associated with perceptions of the spouse as dominant. At the highest level of perceived spouse dominance, CVR was attenuated, again consistent with prediction. Results are discussed in terms of the usefulness of conceptual models of interpersonal relations and motivation as guides in studying the social determinants of CVR, as well as the value of marital interactions as a context for understanding CVR.