Three studies examined cardiovascular (CV) responses during emotional expression with empathically responsive strangers. Study 1 demonstrated that self-relevant emotional expression fostered CV reactivity consistent with challenge. Study 2 manipulated content of discussion by assigning participants to 1 of 4 conditions: emotional, nonemotional, emotional suppression, nonemotional suppression. In same-sex dyads. emotional expression elicited CV challenge reactivity whereas emotional suppression evoked CV threat reactivity, both compared with appropriate control groups. In opposite-sex dyads, however, emotional expression engendered CV threat. Because same- and opposite-sex disclosures differed, Study 3 controlled the content of emotional expression while manipulating gender context. Results confirmed findings from the first 2 studies, indicating that both context and content of emotional expression influenced CV effects. Findings are discussed within a theoretical challenge and threat perspective.