Attaining the vision for science teaching and learning emphasized in the Framework for K-12 Science Education and the next generation science standards (NGSS) will require major shifts in teaching practices in many science classrooms. As NGSS-inspired cognitively demanding tasks begin to appear in more and more science classrooms, facilitating students' engagement in high-level thinking as they work on these tasks will become an increasingly important instructional challenge to address. This study reports findings from a video-based professional development effort (i.e., professional development [PD] that use video-clips of instruction as the main artifact of practice to support teacher learning) to support teachers' learning to select cognitively demanding tasks and to support students' learning during the enactment of these tasks in ways that are aligned with the NGSS vision. Particularly, we focused on the NGSS's charge to get students to make sense of and deeply think about scientific ideas as students try to explain phenomena. Analyses of teachers' pre- and post-PD instruction indicate that PD-participants began to adopt instructional practices associated with facilitating these kinds of student thinking in their own classrooms. The study has implications for the design of video-based professional development for science teachers who are learning to facilitate the NGSS vision in science classrooms.