The paper analyses the impact of programme accreditation in Portugal further to the operations of the Agency for Assessment and Accreditation of Higher Education, which were initiated in 2009. Tracking the evolution of study programmes, the paper found that, out of the initial 5262 programmes on offer in 2009/2010, 40% have been either discontinued or not accredited as of July 2015. The analysis revealed differences between the private and the public sectors, with higher proportions of discontinuations and closures in the former. For the discipline with the highest percentage of non-accredited programmes (Law), the main reasons for denied accreditation were analysed. The identified reasons were related to a lack of academic quality, for example, the programmes' lack of compliance with legal requirements regarding teaching staff qualifications and full-time employment, the blurred identity of programmes, undifferentiated between university and polytechnic sectors, or curricular inconsistencies. The paper suggests that the identified reasons are likely to be symptomatic of the quality shortcomings in the provision of higher education programmes in Portugal. The data provide evidence that programme accreditation has had a powerful impact, reducing the number of programmes, increasing the number of PhD holders among teaching staff and raising institutional awareness of quality.