Healthy normotensive men and women (N = 102) underwent a 3-day ambulatory blood pressure (BP) assessment in which a BP reading was taken 5 min into each social interaction. After each interaction, participants completed a diary that included structural categorization of the relationship and ratings of the quality of the relationship with the interaction partner. Random regression analyses revealed that interactions with family members and spouses were associated with lower ambulatory BP. Interactions with ambivalent network members (characterized by both positive and negative feelings) were associated with the highest ambulatory systolic BP, an effect that was independent of the familial effects on BP. Although there were psychological correlates associated with both structural and functional aspects of relationships, no evidence was found that these mediated the primary findings involving ambulatory BP. These data highlight the influence of both structural and qualitative aspects of relationships on ambulatory BP and possibly health.