Faculty from numerous science disciplines have used concept inventories to focus their efforts on a few core concepts and ways of thinking in introductory courses. These inventories also help faculty recognize students' misconceptions and faulty reasoning from the onset of a course and track gains in understanding as the course progresses. The biology concept inventories that several groups of biologists and educators are now working on will add significantly to the few that have already been published. This article introduces biology faculty to concept inventories, including what they are and how they are developed and used. In addition, I propose next steps, which would lead to faculty development workshops based on the use of concept inventories, student-active teaching, and scientific teaching in introductory biology courses. These workshops could be offered through professional biological societies and coordinated by societies' educators working together on common goals and strategies.