In debate on professionalisation of early childhood education and care professionals (ECEC professionals), the focus is increasingly turning to the ability of ECEC professionals to reflect on and evaluate their own pedagogical practice. Self-reflection is considered a core competence of professional pedagogical practice. So far, little research has been done on the potentials and challenges of self-reflection [Fukkink, R. G., & Tavecchio, L. W. C. (2010). "Effects of Video Interaction Guidance on early childhood teachers." "Teaching and Teacher Education," 26(8), 1652-1659; Girolametto, L., Weitzman, E., & Greenberg, J. (2004). "The effects of verbal support strategies on small-group peer interactions." "Language, Speech, and Hearing Services in Schools," 35, 254-268]. The goal of this study is to gain insight into the self-reflection processes of ECEC professionals during video-stimulated recalls. The recalls show ECEC professionals viewing a picture book together with a child. These videotaped situations function as the stimulus and the object of the self-reflection process. The documentary method is used to reconstruct how subjects described their interactive behaviour, focussing on the strategies that ECEC professionals employed to support children's language development. The study also analyses how the subjects mastered the task of self-reflection. The ECEC professionals' self-evaluations of their own behaviour were complement to external observations made with the help of a standardised instrument (referred to as DO-RESI; [Fried, L., & Briedigkeit, E. (2008). "Sprachförderkompetenz. Selbst- und Teamqualifizierung für Erzieherinnen, Fachberatungen und Ausbilder." Berlin/Düsseldorf/Mannheim: Cornelsen]). The findings indicate how self-reflective conversations need to be conducted in order to enhance the professional development of ECEC professionals.