This article examines one aspect of the growing complexity of relationships between post-compulsory educational institutions in the United Kingdom: a growth in collaborative arrangements between higher education institutions and providers of sixth-form education. The research presented focuses on the characteristics of those schemes either in operation or being proposed at the time of the research, involving sixth forms in schools and colleges and higher education institutions. The article also considers how such schemes might be further developed if such collaborative activity is to become an established feature of the education system in England and Wales. Significant variations in the types of programme, reflecting the diversity of the higher education and sixth-form institutions involved, are reported, and a range of as yet unresolved issues relating to trans-sector collaboration are discussed. The article concludes with a consideration of the future prospects of such schemes. (Contains 1 figure, 1 table, and 1 note.)