There is a significant amount of research into gender differences in academic performance in the science, technology, engineering and maths (STEM) fields. This has identified important differences between the academic achievement of men and women as measured through grade point averages and time to completion. However, the specific STEM fields of design have not been thoroughly explored. This research investigates the long-term academic performance of a large group of architecture, industrial design, interior design and landscape architecture students at a major Australian university. The study followed the progress of 472 students over an 11-year period. In most fields the academic achievement of students follows expected patterns; the difference in academic grades for male and female students reduces over time. However, in interior design, there are significant differences that increase with time, to the favour of women. A range of social, cultural and contextual influences are discussed including the signature pedagogy of the design studio and the hidden curriculum of design education.