This paper starts from the understanding that teachers' knowledge is situated, grounded in knowledge derived from formal training and from experiences in practice. Based on this understanding we examine teachers' reasoning in relation to the pedagogical choices teachers make while using ICT in practice. We argue that teachers' reasoning about pedagogy elicits their technological pedagogical knowledge (TPK). Data from 29 video cases show how elementary teachers used ICT to facilitate specific pedagogical strategies (e.g., activating learning, classroom management, dealing with diversity, fostering learning strategies). Findings indicate that teachers used ICT mostly to promote activation of learning. Many teachers reasoned about using ICT for adapting their teaching to student needs, but this was seldom observed in practice. The few teachers who showed behaviour supporting adaptive teaching and fostering learning strategies almost always used ICT to facilitate these pedagogical strategies. We argue that for effective teaching with ICT it is important that teachers learn to reason explicitly about how ICT can support specific pedagogical strategies. The results from this study provide suggestions for what is needed in teacher education programs and professional development initiatives to support teachers in acquiring TPK.