While the benefits of social support for physiological health are well established, the underlying pathways by which support can influence cardiovascular reactivity (CVR) are still being elucidated. In the present study, we adapted an attachment framework to further explore the support-CVR link. Specifically, we experimentally tested the effect of attachment and social support on CVR by manipulating the provision of invisible support from a stranger, across individuals with secure, anxious and avoidant attachment styles. Employing a 3 ? 2 design, a sample of young adults (N = 138) from across each of the three attachment styles were randomly assigned to either an invisible support (from a stranger), or no support, condition. All participants were subject to an acute standardised stress testing protocol where cardiovascular indices were monitored throughout. Results from a factorial ANOVA showed no significant interaction between support and attachment on any cardiovascular reactivity parameter (SBP, DBP, HR) or any main effect of attachment or support. These findings suggest that, in this case, social support was not effective in buffering the effects of stress across various attachment styles. The benefits of incorporating a developmental perspective to the study of social support and health are discussed.