Pre-service teachers are expected to teach the digital-native generation of students in the information and communication technology (ICT)-enriched school environments. The aim of this study is to better understand their usage of ICT tools and YouTube for teaching during their teaching practicums. Multiple data sources, including interviews, observation of class sessions, a questionnaire and relevant materials, were collected in a teacher education institution in Hong Kong. The results reveal that their ICT usage is high and YouTube is useful for teaching at all three school levels: kindergarten, primary and secondary. The constraints and affordances of YouTube for teaching were identified, namely 'information', 'demonstration' and 'open-ended constructivist'. However, the pre-service teachers have not fully utilized this ICT tools as part of the constructivist approach. Implications for educators are discussed.