To evaluate blood pressure reactivity in children and its changes in adolescents, the acute pressor response to a video-game stress test and the noninvasive ambulatory blood pressure monitoring were evaluated in 62 healthy children divided into three age groups. Basal blood pressure values were measured according to the NIH Task Force. With baseline measures and body mass index controlled for, analysis of covariance showed that the video game provoked significant and incremental cardiovascular reactivity across the games in adolescents when compared with the two other groups of children. The same group of children showed also a significantly higher systolic ambulatory pressure during the daytime, whereas no significant difference was observed by basal BP measurement. In conclusion an increased reactivity to external stimuli was observed in adolescents, and this pattern was strictly associated with a higher daily blood pressure.