ABSTRACT Background Randomized controlled trials (RCTs) are considered the gold standard for assessing the effectiveness of interventions. At the same time, it is challenging to evaluate interventions using experimental designs in child welfare settings. Objective This study explores the facilitators and challenges faced when carrying out a pilot RCT of a home-visitation intervention, Family Partner, that was implemented within Norwegian child welfare services. Method This study draws on 29 qualitative in-depth interviews and four focus group interviews that were carried out with child welfare workers, managers and stakeholders. Results Results revealed one facilitator and four challenges with carrying out RCTs in child welfare settings: The main facilitator was the staff’s belief in the intervention, while the challenges were 1) ethical concerns in participant recruitment and information sharing, 2) resource management challenges in randomization, 3) emotional strains in response to randomization, and 4) contamination between the intervention and control participants. Conclusion While we present possible solutions to the challenges, our results also highlight the importance of careful planning, preparation, piloting, and using mixed method research approaches when conducting RCTs within child welfare services.