Although adolescents demonstrate capacity for rational decision making, their tendency to be impulsive, place emphasis on peers, and ignore potential consequences of their actions often translates into higher risk-taking including drug use, illegal activity, and physical harm. Problems with judgment and decision making contribute to risky behavior and are core issues for youth in treatment. Based on theoretical and empirical advances in cognitive science, the Treatment Readiness and Induction Program (TRIP) represents a curriculum-based decision making intervention that can be easily inserted into a variety of content-oriented modalities as well as administered as a separate therapeutic course. The current study examined the effectiveness of TRIP for promoting better judgment among 519 adolescents (37% female; primarily Hispanic and Caucasian) in residential substance abuse treatment. Change over time in decision making and premeditation (i.e., thinking before acting) was compared among youth receiving standard operating practice (n = 281) versus those receiving standard practice plus TRIP (n = 238). Change in TRIP-specific content knowledge was examined among clients receiving TRIP. Premeditation improved among youth in both groups; TRIP clients showed greater improvement in decision making. TRIP clients also reported significant increases over time in self-awareness, positive-focused thinking (e.g., positive self-talk, goal setting), and recognition of the negative effects of drug use. While both genders showed significant improvement, males showed greater gains in metacognitive strategies (i.e., awareness of one’s own cognitive process) and recognition of the negative effects of drug use. These results suggest that efforts to teach core thinking strategies and apply/practice them through independent intervention modules may benefit adolescents when used in conjunction with content-based programs designed to change problematic behaviors.