A current characteristic of governance in the public services in England is the advocacy of a permeation of once-discrete organizational and professional structures. New configurations are being called for. Examples are extended schools, workforce re-modelling, and multi-agency working. At issue here is a further indication of this loosening of hitherto discrete roles and structures: that of distributed leadership. When formulated, all of these policies lacked an evidence-base which justified them. To some extent this was due to a weak theoretical base. Emerging as a prominent theoretical position to inform distributed leadership is socio-cultural theory, which includes distributed cognition and activity theory. Two conclusions are drawn from the study here. First, an analysis of the most important contribution to this research--that generated by Spillane and his colleagues in the US--points up some important discontinuities between the socio-cultural approach adopted and its empirical endeavours. That is to say, whilst adhering to a socio-cultural position which regards only process as having any ontological status, Spillane's research nevertheless appears to assign ontological status also to individual agents. Second, in contrast to Engestrom's socio-cultural activity theory, Spillane's socio-cultural approach under-theorizes the question of power in distributed leadership. (Contains 1 figure.)