Whereas various studies have examined the effects of in-service training, relatively little is known about effective approaches for improving interaction skills among pre-service teachers for early childhood education and care. In this study, the evidence-based in-service Caregiver Interaction Profile training course was implemented in Dutch pre-service teacher training. The pre-service teachers on the program with relatively low scores at the pretest showed a significant growth in relation to four interaction skills: sensitive responsiveness, respect for autonomy, structuring and limit setting, and verbal communication. We discuss these results in the context of effective professional development in early childhood education and care.