This study highlights how Familias Unidas, a Hispanicspecific, evidence-based, family centered preventive intervention, progressed from intervention development (type 1 translation; T1) through rigorous evaluation (T2) and examines the role of intervention fidelity-adherence and competence-in a T3 trial. Effects of participant, provider, and organizational variables on direct (observational) and indirect (self-reported) fidelity were examined as were effects of fidelity. Two structural equation models were estimated using data from 367 Hispanic parent-adolescent dyads randomized to Familias Unidas. Facilitator perceptions of parental involvement in schools, school performance grade, and school socioeconomic status predicted indirect adherence ratings, which were positively related to adolescent substance use. Facilitator openness to evidence-based practices was associated with indirect competence ratings, school performance grade and size were associated with direct competence ratings, and direct competence ratings were negatively associated with substance use. Findings highlight unique contributions of direct and indirect fidelity ratings in the implementation of Familias Unidas.