The aim for this paper is to explore how the teachers use dialogues and questions as an instructional tool in science classrooms. The focus is to investigate teachers’ use of questioning during wholeclass sessions. There is a growing consensus when investigating into teaching and learning that the quality of conversation is important for fostering students learning, and that the classroom dialogues could improve significantly in this respect (Alexander, 2008; Littleton & Mercer, 2010; Mortimer & Scott 2003). In this paper I will use video documentation from science classrooms from the PISA+ data to analyze the role of dialogues and discussions during whole class instruction in general and the teachers’ use of questioning in particular. Analyses of 8 lessons of whole class instruction from science classrooms will be used to discuss teachers’ use of questioning as an instructional repertoire. Tentative findings indicate that teachers seem to ask a lot of questions, but with little time spent on giving feedback and responding to students’ answers. Furthermore the questions seem to support dialogism with respect to procedural and interactive participation while substantial issues are hardly explored and discussed.