Internationalisation of higher education plays a key role in ensuring that Europe becomes a smart, sustainable and inclusive economy. Internationalisation encompasses short-term and/or long-term mobility of students and staff, strategic partnerships on education, research and innovation, curriculum development, shared or joint programme offers, intercultural understanding and social engagement, knowledge creation and application, global positioning, increased reputation, visibility and competitiveness. The contribution of international academic staff to the improvement of teaching and the quality of curricula, transfer of good practices, educational methodologies, new classroom technologies and approaches have not been systematically studied yet. These questions remain unanswered because there is a lack of information on foreign academic staff in higher education systems. This report, based on unique data from the European Tertiary Education Register, provides evidence on the proportion of international academic staff based on nationality from 19 countries and more than 1,500 European higher education institutions. It is a first step in addressing the impact of internationalisation on teaching and educational activities.