Purpose: The purpose of this study was to explore the attitudes and beliefs of speech-language pathologists (SLPs) with regard to the Lidcombe Program and Demands and Capacities-based treatment and to examine how these attitudes and beliefs might have changed as a result of participating in the RESTART-study. Method: A focus group meeting with 13 SLPs was organized. The discussion was structured using questions on therapy preference, attitudes about and explicit comparison of both treatments and treatment manuals, and learnings of trial participation. Results: Four main themes were identified. First, a change in attitude toward treatment choice was observed. Second, this change was related to a change in beliefs about the potential of both treatments. Third, aspects of the treatments regarded as success factors were considered. Last, learning outcomes and increased professionalism as a result of participating in the RESTART-trial were discussed. Conclusions: This study showed how attitudes and beliefs of SLPs with regard to the Lidcombe Program and Demands and Capacities-based treatment evolved during a randomized trial. This work increases our understanding of the role of attitudes and beliefs in the uptake and utilization of therapies and demonstrates the importance of collecting qualitative data. Results and recommendations should prove of value in implementing the RESTART-trial results and in training SLPs.