In the field of Literacy Studies, online spaces have been recognised as providing many opportunities for spontaneous and self-initiated learning. While some progress has been made in understanding these important learning experiences, little attention has been paid to teachers' self-initiated professional learning. Contributing to the debates about learning online, this article explores three teachers' self-initiated professional learning about digital technologies through their Personal Learning Networks. It reports the findings from a larger qualitative project and examines how the participants' digital literacy practices shaped their deliberate professional learning. The analysis identified several attributes of the participants' learning which, according to them, made professional learning appealing and effective: social, personalised, active and reciprocal, ongoing and blended. The article concludes by discussing how these findings can be used to draw out implications for teachers' professional learning.