High school students were offered a monetary incentive for participating in research. They were given a choice between a smaller fee immediately or a larger fee one week later. Compared to students who delayed gratification, those who chose the immediate fee showed more self-regulatory deficits. They showed greater involvement with cigarettes, alcohol, and marijuana, had a poorer self-concept and underperformed academically. A replication study with middle-school students and different reward parameters yielded equivalent results. Younger adolescents who chose the immediate monetary incentive showed a similar pattern of problem behaviors as the high school students. The findings indicate that this simple choice-delay procedure yields an unobtrusive behavioral measure of self-regulation and offers a developmentally appropriate extension of the delay-of-gratification paradigm for use with older children and adolescents.