Background: Research has suggested that the pressure of exams could undermine pupils' interest in their subjects, but almost all of this research has been conducted in laboratory settings. The Transfer Test in Northern Ireland provides an unusual opportunity to assess the effects of exam pressure in real life because some 10- and 11-year-olds sit a Transfer Test to be admitted to grammar school while others are not tested until they are 14. Aim: To assess the effect of exams on pupils' interest in their subjects both during the period before the exam and after the results are known. Sample: The sample comprised 66 pupils preparing to sit the Transfer Test and 55 not preparing for the test. Method: Pupils' interest in their school subjects was assessed by questionnaires administered 2 weeks before the Transfer Test and then again 2 weeks after the results were announced. Results: Surprisingly, prior to sitting the test, there was no significant difference in motivation between the test and no-test pupils. However, after sitting the test, the motivation of the test pupils decreased significantly relative to their no-test counterparts, despite the fact that most achieved the grades they needed for admission to grammar school. Conclusions: Exams provide a valuable tool for assessing academic progress, but under some circumstances they can reduce pupils' interest in the subjects they are studying.