Video games are one of the most popular recreational activities among Americans of all ages, especially teenaged boys and young men. Studies of the health hazards of video-game playing have linked seizures, psychologic disturbances, and other health problems with the games. The study reported here measured changes in blood pessure and heart rate that occurred in 23 young men when they played a video game. The mean systolic blood pressure for the entire group was considerably higher during play than before or after and was significantly higher in novice players than in more skilled players. Heart rate was also significantly higher during play. In view of these results, other cardiovascular changes might be expected to occur during video-game playing. Although the changes reported here were minor, even minor cardiovascular alterations could potentially prove serious in persons with cardiovascular disease.