Priority setting tends to take place in health care settings that are hierarchical and politically complex. Fair processes, as defined for example by Daniels' and Sabin's accountability for reasonableness framework, have been identified as essential for securing socially acceptable priority setting decisions. However, power differences in the decision-making context can pose a serious impediment to fair priority setting in health care organizations. Comparatively little attention has been paid to examining the institutional conditions within which priority setting decisions are made. We review a case study of priority setting in hospital operational planning in Toronto, which had been designed by executive leaders to be broadly inclusive of senior and middle-level clinical and administrative leaders. We report three power differences that arose as limiting factors on the inclusiveness of the priority setting process. We argue that these findings have significant theoretical implications for the accountability for reasonableness framework and propose a fifth condition, the "empowerment condition", which states that there should be efforts to minimise power differences in the decision-making context and to optimise effective opportunities for participation in priority setting.