Objective: To promote healthy beverage consumption among 9-12 grade students (ages 14-18) by means of a 4-week curriculum promoting increased awareness of drinks containing added sugar and the association between sugar-sweetened beverage consumption and health risks. Design: Quasi-experimental pre-post design. Setting: High schools in Northern California with at least 50% of students eligible for free or reduced-price meals. Method: A 4-lesson version of the Rethink Your Drink high school curriculum was piloted in three high schools in two northern California counties. Two high schools in the same area served as comparison sites. A survey of beverage-related knowledge, behaviours, perceptions and self-efficacy was administered to intervention and comparison students before and after the intervention. Focus groups with students and an online survey and semi-structured interviews with teachers were conducted following the intervention. Results: Intervention students reported significantly greater frequency of reading Nutrition Facts labels and understanding of beverage choice influences and decreased consumption of diet soda than comparison students. A decrease of 0.26 times per day in consumption of sugar-sweetened beverages relative to the comparison group was not significant. Conclusion: The intervention resulted in some positive outcomes, but improvements in targeted beverage consumption were not significant. Students and teachers want shorter, more engaging and experiential curricula that build on previous learning. Findings point to actionable recommendations for improvement of high school healthy beverage curricula and suggest the need for reinforcement using a multi-level approach.