The study suggests that institutionalisation of a comprehensive and systematic approach to internal quality assurance of higher education institutions inspired by the Bologna Process has regulative, normative and cultural-cognitive dimensions. It includes development of structures and procedures for quality assurance, as well as boosting of the socio-political and cognitive legitimacy of the new approaches to quality assurance and the extent to which new approaches are taken-for-granted. Institutionalisation is primarily pushed forward by administrative and junior academic staff. They use the Bologna Process and the European Standards and Guidelines for furthering institutionalisation of internal quality assurance but also rely on the already institutionalised activities related to quality for demonstrating that the new approaches to internal quality assurance are not entirely alien. The study shows that disciplinary differences matter. In the hard-applied fields the regulative elements seem to be not very important, while in the soft-applied fields the regulative aspects are a necessary condition for further institutionalisation. Furthermore, in cultural-cognitive terms, the hard-applied faculty focuses on quantification and technical aspects of internal quality assurance, while the soft-applied field stresses procedural elements and is more prone to adopt a qualitative approach.