The washback effect is particularly relevant when it comes to high-stakes tests, such as university entrance exams. This article presents a research study performed with the aim of determining the current influence of these exams on the teaching of chemistry in upper secondary education. The study was based on a questionnaire distributed among chemistry teachers --447 participants-- from across Spain. The results show that the chemistry content taught in upper secondary education is closer to what is requested in university entrance exams than to what teachers themselves believe to be important for students to learn. For the aspects examined, significant differences between regions were observed; in fact, relevant changes in the curriculum taught and the teaching methodology were apparent in those regions that incorporated content in their tests which was distinct from the traditional approach. Based on the findings, some implications and suggestions are drawn for future university entrance exams.