Cardiovascular reactivity (CVR), such as increases in blood pressure, during stressful marital interactions have been identified as a possible mechanism linking marital discord with cardiovascular disease (CVD). Both expressions of and exposure to negative behavior during marital conflict may influence CVR, but analytic approaches to date have not permitted firm conclusions as to whether CVR during conflict reflects an individual's own actions, actions of the spouse, or both. Additionally, evidence suggests health-relevant marital interaction varies along the affiliation dimension (i.e., warmth vs. hostility) and control dimension (i.e., dominance vs. submissiveness) of social behavior, but there is much less research on the latter. To address these issues, the present study used the Actor-Partner Interdependence Model (APIM) to examine associations of behavioral measures of affiliation and control with concurrent changes in blood pressure (i.e., CVR) during a marital conflict discussion in 146 middle-aged couples. Factor analyses of observer-coded behaviors during conflict discussions revealed a single factor for husbands and for wives, characterized by high hostility and dominance, and low warmth. The validity of these behavioral factors was supported by their predicted associations with spouse ratings of behavior during the conflict discussions, concurrent increases in anger, and reports of overall marital quality. Although expression of and exposure to negative conflict behaviors were correlated, only expression independently predicted increases in blood pressure. Exposure to negative partner behavior might alter other elements of physiological burden contributing to CVD risk, but the individual's own behavioral expressions are more closely associated with concurrent blood pressure reactivity. (PsycInfo Database Record (c) 2020 APA, all rights reserved).