The article reports on a case study of impact evaluation of external quality assurance, i.e. institutional evaluation including programme accreditation, which was carried out by the Romanian Agency for Quality Assurance in Higher Education at Technical University of Civil Engineering Bucharest in the form of a methodological before-after comparison. The impact evaluation exhibits a marked stability of the attitudes towards quality assurance of different stakeholders on a high positive level. The analysis also shows that teachers, on the average, perceive better and perceive more effects of quality assurance in learning and teaching, and that they experience university leadership as highly supportive for quality assurance. The study further demonstrates that for teachers the perceived amount of benefit surpasses the perceived expenditure. Finally, a series of open answers gives indications for possible improvement of the university's quality assurance and organizational structures.