Young adults born prematurely with very low birth weight (</=1500 g) have higher blood pressure than do their counterparts born at term. We tested whether they also have higher blood pressure reactivity to psychosocial stress, which may be a more-specific predictor of long-term cardiovascular morbidity. Systolic and diastolic blood pressure levels for 44 very low birth weight adults (mean age: 23.1 years; SD: 2.3 years) and 37 control subjects (mean age: 23.6 years; SD: 2.0 years) were measured through noninvasive finger photoplethysmography during a standardized psychosocial stress challenge (Trier Social Stress Test). Baseline and task values and their difference (ie, reactivity) served as outcome variables. In comparison with the control group, the very low birth weight group had 7.9 mm Hg higher diastolic blood pressure during the task and 4.8 mm Hg higher diastolic reactivity, with adjustment for gender and age, height, and BMI at testing. A similar trend was seen for systolic blood pressure during the baseline period and the task, but the group differences were not statistically significant. Our results indicate that very low birth weight is associated with elevated blood pressure reactivity to psychosocial stress and, therefore, may increase the risk of cardiovascular morbidity.