PROJECT SUMMARY/ABSTRACT Since 2017, there has been an exponential growth in youths’ use of electronic nicotine delivery systems (ENDS), both nationally and in the state of Hawai‘i [1, 2]. Recent surveillance data has indicated that 18% of all middle school youth in the state of Hawai‘i currently use an electronic vapor product, ranking first nationally among all states collecting data on middle school youth [1]. Of these youth, 30% are of Native Hawaiian or Pacific Islander ancestry, representing the highest percentage of ENDS use among major ethnic groups in Hawai‘i. Despite these alarming trends, there have been no ENDS prevention programs developed and evaluated for youth in Hawai‘i or for Native Hawaiian youth [3]. Therefore, the purpose of this research proposal is to develop and evaluate a culturally grounded, ENDS prevention intervention for rural Hawaiian youth. This will be accomplished through two specific aims. AIM 1 (Years 1-3) are focused on pre-intervention and intervention development. In Year 1, youth focus groups will be conducted to assess the environmental demands related to ENDS use in rural Hawai‘i. In Year 2, specific ENDS-related problem situations (i.e., situations that increase risk for ENDS use) will be extracted from the Year 1 focus groups and prioritized through survey methods with 200-250 predominately Native Hawaiian youth across 16 different middle/intermediate schools on Hawai‘i Island. In Year 3, five situations found to be the most frequently experienced and/or difficult to manage by youth surveyed in Year 2 will serve as the foundation for the development of narrative scripts. Three of these scripts will be cast and filmed on location on Hawai‘i Island by a professional film director, and will be edited into three short films, 6-8 video clips, and 6-8 professional photos or production stills. Similar to our prior drug prevention research in rural Hawai‘i [4], classroom-based lessons will be created to support the short films. Additional lessons and videos from an evidence-based, culturally grounded substance abuse prevention curriculum for Hawaiian youth (Ho‘ouna Pono) [5] will be used to create a modular classroom curriculum. The video clips and professional photography/production stills will be embedded with prevention messaging, and will be used for a social and print media campaign to reinforce the classroom curriculum. AIM 2 (Years 4-5) is to evaluate the ENDS prevention intervention (classroom curriculum plus social/print media campaign) across all middle/intermediate public or public- charter schools (N = 16) and up to 11 different cultural immersion charter schools on Hawai‘i Island using a dynamic wait-listed control group design [6].