Background & Objectives: Commitment of top managers is one of the key requirements to implement accreditation successfully and that knowledge, attitude, and practice of managers should be studied. Therefore, this study aimed at assessing knowledge and attitude of top managers who involve in accreditation programs in teaching hospitals of Ardabil and East Azarbaijan provinces. Methods: A descriptive study was conducted in 14 teaching hospitals of Ardabil and East Azarbaijan provinces in 2012. A self-administered questionnaire was used to collect data and validity of the questionnaire obtained by expert panel opinions and reliability was attained through half-structure method (α=0.9). In total, 150 individuals were selected through census method. Data were analyzed using SPSS v.16 software. Results: 50.6% of participants were female with the most common education level of Bachelor degree (66%) and the majority was nurses. 63% had low and 11% had good knowledge on accreditation. About 70% of participants believed that accreditation increases public trust, quality of services, patient and staff satisfaction, and services safety as well as decreases hospital costs and improve hospital processes. They also stated that accreditation is more effective and efficient than the current evaluation system. Conclusion: Considering important role of top managers’ knowledge and attitude to implement accreditation processes successfully and low level of their knowledge and high level of attitude planning of proper programs is necessary to improve managers’ knowledge and attain their support and cooperation.