The use of reflection as a learning approach is increasing in medical education, often based on the assumption that students will not reflect without being encouraged to. Personal reflection is used to describe students’ ability to critically reflect on own learning and functioning. The assumption here is also that medical students seem not to reflect spontaneously. We explored students’ level of personal reflection and validated a questionnaire that attempt to measure personal reflection. We translated and adapted the Groningen Reflection Ability Scale (GRAS) to use in a Danish context. It was pilot tested and we further validated the GRAS scale in terms of test-retest reliability and confirmatory factor analysis. With a cross-sectional design, we finally measured the level of personal reflection of the medical students at Aarhus University across all semesters. We present the validated questionnaire and the findings describing the levels of personal reflection from medical students sampled across the semesters at Aarhus University (n=325). We discuss whether a questionnaire method is appropriate for gaining knowledge of student reflection and if we now have an instrument to measure ‘reflective’ outcomes of educational interventions.