In 148 Black and White men and women, laboratory measures of blood pressure (BP), heart rate, stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) during baseline and 5 stressors were examined in relationship to ambulatory systolic (SBP) and diastolic (DBP) blood pressures at work. Baseline BP strongly predicted mean work levels in all groups. For White men and Black women, higher SV and CO responses to the active speech and averaged across all tasks predicted higher work SBP individually and also when added to a model based on baseline SBP, age, and diary information. For White women, higher SBP increases to the passive speech similarly predicted mean work SBP. For Black men, higher TPR response to the cold pressor test correlated with higher work SBP but did not improve a predictor model involving baseline SBP and age. Reactivity measures did not consistently contribute to prediction of work DBP.