This report compares the effects (concurrent and lagged) of the anticipated rewards and costs of violent crime on engagement in severe violence in a sample of male juvenile offenders (N = 1,170; 42.1% black, 34.0% Hispanic, 19.2% white, and 4.6% other; ages 14–18 at baseline). Anticipated rewards (social approval, thrill) are more predictive of concurrent severe violence than are anticipated costs (social disapproval, risk of punishment). The analysis finds no evidence that perceptions of the rewards and costs of violent crime influence engagement in severe violence 6 months later. The results support the view that adolescence is a time of heightened reward salience but raise doubt about the longitudinal predictive validity of perceptions about crime during this time of life.