In recent years the International Baccalaureate (IB) Diploma has become widely accepted as a university-entry qualification in the UK, but there has been little quantitative research into the achievements of IB students at degree level. This study investigates IB students from one selective independent school who entered UK universities between 2000 and 2007, and compares their degree results with those of other groups of qualifiers. The findings indicate that the IB students of this sample were much more likely than other students to achieve good honours degrees, with males more likely to achieve a 1st class degree but females more likely to obtain either a 1st or 2.1. Universities tend to make complicated admissions offers to IB students. We find that both Higher Level points and total Diploma points are related to degree performance, so it could be argued that there is no need for an offer to ask for both. In addition, asking students who apply for degrees in STEM subjects or Economics for a top grade in Higher Level mathematics may not be necessary because subsequent degree performance does not appear to depend on that. (Contains 4 tables and 7 figures.)