Adolescents struggle with setting and striving for goals that require sustained selfdiscipline. Research on adults indicates that goal commitment is enhanced by mental contrasting (MC), a strategy involving the cognitive elaboration of a desired future with relevant obstacles of present reality. Implementation intentions (II), which identify the action one will take when a goal-relevant opportunity arises, represent a strategy shown to increase goal attainment when commitment is high. This study tests the effect of mental contrasting combined with implementation intentions (MCII) on successful goal implementation in adolescents. Sixty-six 2nd-year high school students preparing to take a highstakes exam in the fall of their third year were randomly assigned to complete either a 30-minute written mental contrasting with implementation intentions intervention or a placebo control writing exercise. Students in the intervention condition completed more than 60% more practice questions than did students in the control condition. These findings point to the utility of directly teaching to adolescents mental contrasting with implementation intentions as a self-regulatory strategy of successful goal pursuit.