Salters-Nuffield Advanced Biology is a new advanced level biology course, piloted from September 2002 in England with around 1200 students. This paper discusses the reasons for developing a new advanced biology course at this time, the philosophy of the project and how the materials are being written and the specification devised. The aim of the project is to provide an up-to-date course that interests students, is considered appropriate by teachers and other professionals in biology, and takes full advantage of modern developments in biology and in teaching. (Contains 1 figure and 2 tables.)