In the context of accreditations by independent experts, the University of St.Gallen regularly has itself measured against international quality standards and its quality confirmed by independent institutions. Thus activities at the HSG are also informed by the quality standards of EQUIS and AACSB. In addition, the HSG is audited at a national level.

The European Foundation for Management Development (EFMD) is recognised as a global institution for the accreditation of business schools and their curricula, as well as of technically supported forms of learning. In 1997, it established EQUIS (European Quality Improvement System) as a European accreditation standard which many business schools use to prove their quality. The HSG has been EQUIS-accredited since 2001. In 2013, the EQUIS expert committee accredited the University for another five years. In so doing, the EQUIS expert committee underlined the University's overall quality, which is reflected in its vision and the principles and guidelines derived from it. Also, the experts praised the HSG's substantial progress in internationalisation and programme portfolio. Special mention was accorded to the Master's programme in Strategy and International Management (SIM-HSG), which has repeatedly been ranked in first place in the Financial Times's worldwide ranking of Master's programmes in Management.

The fact that the University of St.Gallen is among the frontrunners in the field of management education is also confirmed by the report of the Association to Advance Collegiate Schools of Business (AACSB). The HSG was first accredited by AACSB in 2003. The HSG was thus the first university in the German-speaking area to have earned EQUIS and AACSB, the two most demanding international seals of approval for business schools. The HSG was last accredited by AACSB in 2014. At that time, the assessment team particularly emphasised the alumni network, the long-term relationships with many companies, the strong and cooperative faculty culture and the HSG's excellent reputation in the region, as well as its positive impact on the city and the canton.

International accreditations are important for the HSG to be able to attract first-class students and faculty. They reinforce the international brand of the University of St.Gallen. In addition, the seals of approval pave the way for an exchange with other accredited universities and are conducive to the pursuit of continual improvement.

In 2014, the University satisfied the requirements of the third quality audit of all the state universities of Switzerland. Besides offering suggestions for further improvement, the auditors congratulated the HSG on its excellent overall performance and declared that "Switzerland can be really proud of having one of the best business universities worldwide".