Abstract Introduction Knowledge, once acquired, degrades over time. Exams that contain questions related to previously acquired knowledge (‘retrieval practice questions’) may promote retrieval practice and spaced learning, and subsequently prevent knowledge loss. To investigate this hypothesis, we compare the score of retrieval practice questions to regular questions in exams of a two-year (bio)medical study program. Methods The two-year “Mechanisms of Health and Disease”-program for biomedical sciences and medical students in Nijmegen (the Netherlands) contains 14 spaced exams of 80 questions each. The percentages of correct-, false-, and non-answers were compared between regular questions and retrieval practice questions. Using Pearson correlations between question scores and exam scores (RiT-values), the impact of retrieval practice questions on the internal consistency of exams was determined. Mixed model analyses determined changes in outcomes across time. Results Analysis of 2006 regular questions and ...