For Virtual Patient-based exams, several scoring and grading methods have been proposed, but none have yet been validated. The aim of this study was to evaluate a new scoring and grading model for VP-based exams in postgraduate paediatric nurse education.The same student group of 19 students performed a VP-based exam in three consecutive courses. When using the scoring and grading assessment model, which contains a deduction system for unnecessary or unwanted actions, a progression was found in the three courses: 53% of the students passed the first exam, 63% the second and 84% passed the final exam. The most common reason for deduction of points was due to students asking too many interview questions or ordering too many laboratory tests.The results showed that the new scoring model made it possible to judge the students' clinical reasoning process as well as their progress. © 2015 Elsevier Ltd.