ObjectiveThe objective of this study was to examine the effects of partner interactions on ambulatory blood pressure in a sample of 120 healthy adults who were monitored over a 6-day period.MethodsAfter each blood pressure measurement, participants rated characteristics of ongoing social interactions, along with emotional activation, physical activity, talking, posture, and other covariates, with computer-assisted self-report assessments.ResultsUsing multilevel modeling, we showed that blood pressure was significantly lower during social interactions with one’s partner relative to social interactions with any other person and relative to periods of not interacting. Interactions with partners also were characterized by significantly less talking and emotional activation and more intimacy and perceived emotional support; however, these differences did not mediate the partner effect on blood pressure. In addition, the relative benefits of interacting with a partner were not moderated by relationship quality, gender, or race.ConclusionsThe effects of social situations on ambulatory blood pressure may represent one pathway through which social relationships affect cardiovascular health.