Objective: A school-based nutrition education minimal intervention (MI) was evaluated. Design: The design was experimental, with random assignment at the school level. Setting: Seven schools were randomly assigned as experimental, and 7 as delayed-treatment. Participants: The experimental group included 551 teens, and the delayed treatment group included 329 teens. Intervention: The minimal intervention was "Present and Prevent," a commercially available PowerPoint program presented in two 30-minute time slots over 1 week. Main Outcome Measures: The dependent variables were nutrition knowledge, attitudes, peer and family influences, behavioral intentions, and program satisfaction. The independent variable was group assignment. Analyses: A matched-pairs and 2-sample t test were used respectively to assess within-group and between-group changes. Results: Significant experimental posttest improvements occurred in the following: knowledge (P less than 0.001); intention to maintain a healthy body weight because of importance to friends (P less than 0.001); and intention to eat fewer fried foods, eat fewer sweets, look more at food labels, and limit TV watching (all P less than 0.001). Program satisfaction measures were significantly associated with each of the healthy weight maintenance behavioral intentions. Conclusions and Implications: The MI teen obesity prevention program made an impact on nutrition knowledge and positive behavioral intentions in only 2 classroom sessions and was well received by participants.