While perceived social support appears to be associated with buffered cardiovascular reactivity to short-term stressors, its impact on cardiovascular recovery is less clear. This relationship might be affected by trait hostility, with hostile individuals benefiting less from social support. However, despite the possibility that support provision might enhance well-being, limited empirical work has manipulated this in a laboratory context. The present study sought to investigate whether mentally activated support provision and support receipt influenced cardiovascular recovery from cognitive stress. Systolic blood pressure, diastolic blood pressure, heart rate, cardiac output, and total peripheral resistance were monitored continuously in a laboratory following exposure to a short-term cognitive stressor. Mixed factorial analyses of variance revealed that inducing thoughts of support provision resulted in elevated post-stressor systolic and diastolic blood pressure responses (p=.03: p=.004) in comparison to thoughts of support receipt or non-supportive social contact. Furthermore, these elevations were most pronounced for individuals high in trait hostility. From this study, support provision when already cognitively and physiologically stressed appears to be deleterious rather than beneficial for cardiovascular function. Moreover, individuals high in trait hostility may be particularly disadvantaged by providing support in everyday life. (C) 2012 Elsevier B.V. All rights reserved.