Many refugee children experience trauma in early childhood. Effective, tailored interventions are needed to improve refugee children's access to preventive mental health. We interviewed refugee-serving stakeholders and parents participating in an evidence-based preventive mental health and wellness intervention adapted for Afghan refugee children and families who may have experienced trauma. Interview guide development was informed by two implementation science frameworks: the Consolidated Framework for Implementation Research and the Model for Adaptation Design and Impact. A three-person team coded transcripts via rapid qualitative analysis, and the study team reached consensus on themes. Six refugee-serving facilitators and five refugee parents discussed key determinants of successful implementation. Themes included: (i) modeling cultural humility to promote communication about emotions; (ii) needed linguistic support and referral networks to avoid miscommunications and missed communications; (iii) bridging connections between children, families and schools; (iv) different takeaways, or differing goals and expectations between facilitators and participants; and (v) timely, specific cultural considerations to overcome participation barriers. Overall, we found key determinants of successful implementation of a preventive mental health and wellness intervention for refugee children and families included adaptations to enhance cultural humility and sensitivity to cultural context while strengthening communication among facilitators, children and families.