Important elements in the curriculum at the Faculty of Health Sciences in Linköping are vertical integration, i.e. integration between the clinical and basic science sections of the curriculum, and horizontal integration between different subject areas. Integration throughout the whole curriculum is time-consuming for both teachers and students and hard work is required for planning, organization and execution. The aim was to assess the importance of vertical and horizontal integration in an undergraduate medical curriculum, according to opinions among students and teachers. In a questionnaire 102 faculty teachers and 106 students were asked about the importance of 14 different components of the undergraduate medical curriculum including vertical and horizontal integration. They were asked to assign between one and six points to each component (6 points = extremely important for the quality of the curriculum; 1 point = unimportant). Students as well as teachers appreciated highly both forms of integration. Students scored horizontal integration slightly but significantly higher than the teachers (median 6 vs 5 points; p=0.009, Mann-Whitney U-test), whereas teachers scored vertical integration higher than students (6 vs 5; p=0.019, Mann-Whitney U-test). Both students and teachers considered horizontal and vertical integration to be highly important components of the undergraduate medical programme. We believe both kinds of integration support problem-based learning and stimulate deep and lifelong learning and suggest that integration should always be considered deeply when a new curriculum is planned for undergraduate medical education.