The implementation of social media tools in organisations, known as enterprise social networking (ESN), provides a convenient means for staff to share knowledge in informal settings and arrangements. ESN can be used to support a knowledge management technique known as communities of practice (CoP), and the use of ESN and CoP for organisational knowledge sharing is the subject of increasing interest and research as awareness of the potential benefit for organisations grows. Action research (AR) is seen as a suitable approach for studies in this field where ESN are implemented in organisations and the results can be observed and analysed, leading to further change. This paper describes an AR study that examines how ESN can enable staff knowledge sharing in virtual CoP (vCoP) in a higher education context. The AR study consisted of three cycles running over a 12 month period, and each cycle consisted of a five-phase approach of Diagnosing, Action Planning, Action Taking, Evaluating, and Specifying Learning, with the outputs from each cycle informing a package of interventions for the next. The data collection instruments used for the study were focus groups, semi-structured interviews and content analysis, underpinned by reflective journaling. The suitability of the AR approach adapted for this study is examined by critiquing the methods and practices applied to the study, and considering issues of validity, reliability, generalizability, and ethics, focusing on the professional, personal, and political dimensions of AR that were encountered. Drawing on the experiences of this AR study, a number of improvements over the original research design are suggested. This paper should be of use to those who are undertaking AR studies in this field and in similar organisations. It will also add to the body of literature examining AR as a suitable and valid method for information systems and organisational change research.