Research demonstrates that attempts to improve the quality of education in higher education institutions (HEIs) through external quality assurance (EQA) systems have not always produced the expected results due to the complex nature of education and scepticism regarding the applicability of EQA systems to education. It frequently resulted in escalating tensions and distrust between academics and policymakers. The 2004 implementation of accreditation by the National Commission for Accreditation and Assessment (NCAAA) in the Kingdom of Saudi Arabia (KSA) intended to improve the education of HEIs and ensure the application of high standards. This mixed-methods research study aims to evaluate the impact of academic accreditation in KSA after nearly two decades of implementation. We collected quantitative data from participants at ten accredited universities using two self-designed Likert-scale surveys based on the NCAAA accreditation standards and ten semi-structured interviews for the qualitative data. The results indicate significant improvements but highlight some imperfections and contradictions that make it essential to ascertain our findings cautiously. This study demonstrates the value of qualitative data to better evaluate the effectiveness of EQA instead of a single quantitative approach.