Effective professional learning for teachers is fundamental for any school system aiming to make transformative and sustainable change to teacher practice. This paper investigates the efficacy of Twitter as a medium for teachers to participate in professional learning by analysing the tweets of 30 influential users of the popular medium. We find that Twitter primarily acts as a valuable conduit for accessing new and relevant educational resources on the internet and also as a viable means of social support for like-minded educators. The cost effective nature of the microblogging platform ensures that it can act as a medium for sustained professional development, while leaving the individual participants to control and take ownership of the learning. These features align with the current literature associated with the characteristics of effective professional learning. (Contains 3 tables and 1 figure.)