Abstract Background Family risk factors, e.g. low socioeconomic status or parental mental health disorders, can affect children’s health and development. Thus, targeted preventive services for families with psychosocial burden are crucial. The German Early Childhood Intervention (ECI) program is a preventive approach that aims to strengthen parent’s resources by supportive services. However, research has revealed that only a proportion of the families considered to have substantial risk factors access the ECI program. To increase pediatricians’ skills in identifying risk factors, and to improve the cross-sectoral collaboration between relevant professionals and the referral of families to supportive services, the PATH-intervention (Pediatric Attention To Help) was developed. The PATH-intervention includes interprofessional quality circles and a one-day training program for the pediatricians. This study aims to evaluate this complex cross-sectoral care intervention for families with psychosocial burden. Methods Using a prospective quasi-experimental, controlled (matched-pair), longitudinal mixed-method design, we will compare families under treatment of pediatricians trained in the PATH-intervention with families under treatment of a control group of pediatricians. Participating families are asked to complete online-surveys. As a primary outcome, we will examine the use of supportive services of the ECI by burdened families. Secondary outcomes are the proportion of correctly identified families with psychosocial burden by the pediatricians, as well as information provision and motivation of the families to use the supportive services. Additionally, the cost-effectiveness ratio will be investigated. In the process evaluation, we will qualitatively explore the acceptance of the PATH-intervention of all involved stakeholders and the treatment fidelity of the trained pediatricians. Discussion This study will determine whether the PATH-intervention enables the pediatricians to identify and recommend supportive services to burdened families, as well as the families’ use of the supportive services of the ECI. Qualitative data will give insight into the acceptance of the intervention from the perspective of all stakeholders and the treatment fidelity. Results of this study could be the starting point for the broader implementation of the PATH-intervention as standard care. Trial registration German Clinical Trials Register (DRKS): DRKS00023461 (3rd December 2020); WHO UTN: U1111- 260-6575.