Abstract Background The My Positive Health (MPH) dialogue tool for children was developed to aid children and teenagers in reflecting and communicating about their health from a broader perspective. This study investigates facilitators and barriers to implementation in pediatric care and assesses experiences of healthcare professionals (HCPs) and children regarding effectiveness. Methods We conducted a mixed-methods study involving six Dutch pediatric outpatient clinics. Quantitative data on facilitators and barriers were obtained from 18 out of 20 participating HCPs (pediatricians, nurse practitioners and physician assistants) using the Measurement Instrument for Determinants of Innovations. Additionally, qualitative insights were gathered through semi-structured interviews with 17 HCPs and 30 children (8–18 years old) with chronic conditions. Results Facilitators identified in both user and innovation domains included improved patient understanding and the tool’s simplicity, while barriers involved organizational constraints and integration issues, for example limited resources and lack of organizational support. Participating HCPs highlighted the tool’s role in fostering person-centered conversations, especially for children with chronic conditions. Children positively viewed the tool, noting its ability to enable deeper, personalized interactions with HCPs. Conclusion This study on the implementation of the MPH dialogue tool for children in pediatric care highlights its user-friendliness and relevance, alongside challenges like organizational constraints. Beneficial for person-centered care and children’s active participation, the tool enhanced healthcare dialogues and empowered children in their health journey. However, HCPs faced integration challenges within existing practices. Addressing these barriers and providing organizational support are vital for effectively implementing the MPH dialogue tool and optimizing pediatric patient engagement and care quality.