Socio-technical transition theory is increasingly being used in research and practice to explain and guide transitions toward sustainability. Although recognizing the coevolution of technology and society, multi-scalar influences, and complex social processes, transition theory has thus far inadequately accounted for the role of power and in shaping transitions. This study uses the example of the transition-in-progress toward more sustainable e-waste practices in South Africa as one illustration of how power shapes the successes, failures, and direction of transitions. I look specifically at three transition arenas that are competing for legitimacy to guide the South African e-waste transition and show how their history, membership, and rules of participation shape the different pathways promoted by these organizations. In the South African case, vested interests and constraints on participation resulted in the splintering of original transition arena. While socio-technical transition theory suggests the importance of different competing niche experiments, in this case, different pathways are being promoted by different coalitions of actors through different arenas. The presence of multiple arenas and pathways has divided resources, created confusion, and arguably delayed the transition. Further, the scope for participation in these organizations differs, and this has implications for the redistribution of power. I suggest the need to more carefully consider the role of power, trust, and legitimacy within socio-technical transition theory and specifically within the transition arena. Importantly, analyzing the transition arena as a site of contestation over the distribution of costs and benefits of the particular pathway will enhance socio-technical transition theory's explanatory power regarding how and why particular outcomes emerge.