The CHIME-A gives comprehensive coverage of eight aspects of mindfulness drawn from various definitions of this complex construct, opening the way for finer grained mediation research in young people. Based on a 37-item 8-factor adult measure, the Comprehensive Inventory of Mindfulness Experiences (CHIME), we undertook language simplification, exploratory and confirmatory factor analysis, resulting in a 25-item measure demonstrating the same 8-factor structure (the Comprehensive Inventory of Mindfulness Experiences – Adolescents; CHIME-A) in young adolescents (ages 12–14 years). The ability to isolate, amplify, and compare different elements of mindfulness will assist in optimizing the effectiveness of MBIs in youth. Further, the ability to measure how aspects of mindfulness naturally unfold during development might allow age-matching of key skills in sequenced MBI modules.