Science teacher leadership has been identified as an important factor in the improvement of science education. However, there is wide variation in how leadership roles are assigned or taken up by science teachers. This makes designing professional development for science teacher leaders challenging. In this article, we present an activity designed to support science teacher leaders in identifying the leadership roles they occupy and the roles they would like to develop further through professional development. We present data from a group of science teacher leaders who participated in a professional learning program supported by a large science museum. Based on the data we collected, we provide a snapshot of how we interpreted that data and identify professional learning needs and possible resources for the science teacher leaders in the program.