John Henryism, a coping style characterized by a strong predisposition to confront daily psychosocial stressors in an active and effortful manner, has been associated with cardiovascular (CV) disease risk in adults. This study examined the relationship of John Henryism to CV functioning at rest and during laboratory stressors (i.e. forehead cold stimulation, postural change, and treadmill exercise) in 173 normotensive 10-to 17-year-old African-American and White children. High John Henry scores were associated with higher blood pressure, higher total peripheral resistance, and lower cardiac index at rest. These relationships were qualified by an interaction with socioeconomic status (SES) such that those from lower SES backgrounds who were high on John Henryism had particularly high levels of resting CV measures. No significant associations were observed with CV reactivity to the stressors. Findings are discussed in terms of possible impact of coping styles to environmental stress upon physiological functioning and health.