In STEAM (Science, Technology, Engineering, Arts, and Math) instruction, inquiry and authentic problem solving connect the disciplines to encourage higher-order thinking and increase student engagement. For instruction to be successful in facilitating meaningful student thinking about authentic problems, however, the instructor needs to use strong questioning techniques. This study explored what questioning techniques teachers use as they enact STEAM instruction in their classrooms. Eight middle school teachers who had designed authentic STEAM lessons were observed and scored on a rubric reflecting various components of STEAM instruction as they implemented their lessons. Then transcripts from these lessons were coded to identify the types of questions teachers asked. These questions were identified as inquiry-based or non-inquiry-based using Llewellyn's categories of inquiry-based questions. Findings show that teachers who scored lower on the rubric asked inquiry-based questions no more than 50% of the time, while teachers who scored higher on the rubric asked inquiry-based questions more than 70% of the time.