Implementing teaching enhancement is especially challenging when undertaken on a large-scale and with a range of participating institutions and stakeholders. This study sought to advance understanding of this under-researched area through cultural-historical activity theory, investigating four government-funded, cross-institutional teaching enhancement projects over a three-year period. Analysis of documentary, interview and survey data showed multiple contradictions within and between the activity systems representing the projects and the teaching practices in the involved academics' home departments, which constrained their impact. Through expansive learning cycles, however, the project teams found a way forward through distributed leadership, creatively aligning the project outcomes with institutional or departmental priorities. The distributed leadership practices also nurtured the skills of these academics in leading in their localised departmental settings, bringing about discipline-grounded teaching enhancements.