Developmental research suggests that adolescents may be highly influenced by their peers to take risks. Although youths with callous-unemotional (CU) traits engage in high-risk behaviors in the form of antisocial behavior and aggression, little is known about their decision making, particularly when their peers are present. Youths high on CU traits may be most susceptible to influence, especially when rewards are involved, or they may be highly rational relative to their low CU peers and less susceptible to social peer pressures. The present study used a gambling task with 675 youths (female n = 348), ages 16 to 20 years (M = 16.9, SD = .8). The majority were White British (64%). We experimentally manipulated whether youths made decisions in groups with peers or individually. All members of the group reported on their CU traits. Using multilevel modeling to control for group-level effects, youths with higher levels of CU traits were found to be less sensitive to accruing rewards on the gambling task than youths low on these traits. When in groups, male participants with higher levels of CU traits made quicker decisions to take risks than male participants lower on CU traits, particularly after punishment. Youths with CU traits are distinct in showing a lack of emotion and this may facilitate heightened rationality in responding to rewards. However, results suggest that male adolescents who are high on CU traits may react to the possible frustration of losing by attempting to gain back rewards quickly when their peers are watching.