This thesis explores the professional discretion in relation to national inspections by focussing on the Swedish national school inspection (SNSI) and how the inspections made can affect the professional discretion. During the last decades the Swedish welfare sector has gone through a remarkable shift towards using new public management (NPM) reforms, implementing market solutions with the aim to increase cost efficiency and quality. These reforms have caused a huge impact on the education system in Sweden, such as the privatisation of schools and shifting responsibility from the state to the local municipalities. The development of the NPM has also increased the auditing in order to assure that welfare service produces high quality services, where national inspection has been an increasingly popular method of auditing. Extensive research studying the relationship between auditing and de-professionalization is available and many argue that auditing decrease the professional discretion. Despite the research, there is an empirical gap to how national inspection affects professional discretion. This is surprising as national inspections at least theoretically should be able to both undermine and support professional discretion. The controlling inspection type can from this view be argued to undermine professional influence by using top-down steering not considering professional knowledge and experience. The supporting inspection type uses more bottom-up strategies in dialogue with the professions and can theoretically thus be seen as more supporting of professionalism. The aim of this thesis is to initiate the bridging of this gap by analysing the SNSI different inspection types in relation to professional discretion. The results of the study suggest that the SNSI uses two controlling type of inspections as well as one new supporting type of inspection. The supporting inspection type is found to undermine professional discretion, while the two different controlling inspections both support and undermine the professional discretion depending on how the inspection is conducted. This gives evidence to how a supporting inspection type actually can undermine professional discretion more than the controlling inspection types.