This study aimed to explore preschool teachers’ actions in order to support children’s learning processes in a context where an interactive whiteboard (IWB) is used. Five preschool teachers and 22 children aged 4–6 were video observed in 2017 and early spring 2018 over a period of 5 months. The findings of the study revealed 21 scaffolding actions which preschool teachers used including: Concretizing, Questioning, Instructing, Providing space, Affirming, Providing feedback, Inviting, Watching, Laughing together, Approaching, Standing/sitting beside, Simplifying, Filling in the blanks, Confirming, Participating, Challenging perception, Challenging thought, Explaining facts, Displaying, Explaining solutions, and Referring back. By characterizing teachers’ actions in relation to different scaffolding functions, the relationship between action and scaffolding function was particularly clarified. Six of the functions, including recruitment, direction maintenance, marking critical features, reduction in degrees of freedom, frustration control and demonstration were aligned with Wood et al.’s (Child Psychol Psychiatry 17:88–100, 1976) theoretical framework. By identifying two additional functions, i.e., mutual enjoyment and participation in the activity, more importantly the study contributed to the development of Wood et al.’s (Child Psychol Psychiatry 17:88–100, 1976) theoretical framework. It can be said that the findings of the study expanded and deepened our understanding regarding scaffolding processes and the ways they can be implemented in teaching practices.