Background and Objective:
Accreditation programs have many benefits that contribute to a more effective and efficient performance of the healthcare institutions: improvement in organizational efficiency, cost reduction, better communication between professionals and consequently improved teamwork and greater satisfaction on the part of users. The National Health Accreditation Program (NHAP) was implemented in 2009 due to the need to standardize the accreditation of all healthcare institutions and it was adapted from the Quality Model of the Andalucia Agency (ACSA). The main goal is to evaluate three models used to accreditate healthcare institutions, comparing their methodologies and verify which model is more suitable to the Portuguese reality.

Methods:
It was revised three accreditation models, such as the Joint Comission International, the Caspe Healthcare Knowledge Care and the ACSA that were compared taking into account the eight principles of certification of the ISO 9000.

Results:
The ISO 9000 certification is not fully adapted to the healthcare units, but has eight principles that are a good referential to establish comparations. It was found that ACSA model is suitable for most portuguese healthcare institutions, since it takes into account all the principles of ISO certification - customer focus, leadership, involvement of people, process approach, system approach to management, continual improvement, factual approach to decision-making and relationship management, and it was built for a similar reality to the Portuguese health system – the spanish one, so it was a good basis to build the NHAP.

Conclusion:
NHAP has adequate characteristics and answers to the main needs of the Portuguese health system and it’s suitable for most healthcare institutions.