Background: Recent changes to undergraduate (basic) medical education in Ireland have linked an expansion of student numbers with wide-ranging reforms. Medical schools have broadened access by admitting more mature students from diverse backgrounds and have increased their international student numbers. This has resulted in major changes to the demographic profile of students at Irish medical schools.Aim: To determine whether the demographic characteristics of students impact on their academic performance and specifically on their rate of knowledge acquisition.Methods: As a formative assessment exercise, we administered a progress test to all students twice each year during a 4 year graduate-entry medical programme. We compared scores over time between students from different age cohorts, of different gender, of different nationalities and from different academic backgrounds.Results: In the 1143 tests taken by 285 students to date, there were no significant differences in the rate of knowledge acquisition between the various groups. Early in the course, students from a non-biological science background performed less well than others but outperformed their peers by the time of graduation.Conclusion: Neither age, gender, nationality nor academic background impacts on the rate of knowledge acquisition among graduate-entry medical students.