Exergames, which are video games that require gross motor activity, are popular activities that produce energy expenditure. Seventy-four low-income African American 12- to 18-year-old adolescents were randomly assigned to a 30-minute condition: 1) solitary Wii tennis exergame play against virtual peers; 2) social Wii tennis exergame play against a real peer; or 3) control group with sedentary computer activity. Adolescents were tested for caloric expenditure after exposure to treatment conditions as well as on a tennis court using Actical accelerometers. Adolescents who played the social exergame against a peer expended significantly more energy than those who played alone. Both exergame groups expended more energy than the control group. Adolescents who played the social exergame also expended comparable calories to actual tennis court play during a simulated lesson. Exergames, then, could promote physical activity, thereby becoming a tool to combat the obesity crisis that is affecting many youth.