Many eco-innovations have been linked to technical change in the ICT domain. Leveraging the distinctive features of general purpose technologies, ICT have the potential to steer green growth and to help decouple this growth from ecological damage. The paper aims to shed light on innovation dynamics in this emerging sector by investigating the patterns of innovation in the green ICT domains using granted EPO patent data from 1986 to 2006. By means of a network analysis, it identifies existing green ICT domains and examines the characteristics of innovative activity in these domains, focusing in particular on growth and technological pervasiveness, as well as on the variety of innovators. Results indicate that the innovative activity in green ICT domains is characterised by high growth and high levels of technological pervasiveness, considerable entry of new innovators and a variety of actors � with a prevalence of large ICT firms and universities. However, the analysis highlights the existence of three different clusters � emerging fields, established fields and mature fields � that are defined by different structures of innovative activities and by different technological opportunities.