Purpose: The hospital accreditation system in Iran is relatively young, having been intro-duced in 2012. Therefore, there is a real need for research on the status and impact of hospital accreditation in Iran. The purpose of this study was to evaluate and compare attitudes towards accreditation and quality improvement activities among hospital employ-ees, specifically the attitudes towards the impact of accreditation on the quality of healthcare and its benefits in Iran. Materials and Methods: A cross-sectional survey was carried out at 23 teaching hospitals in three metropolises in Iran, all of which successfully passed national accreditation surveys. Some 1213 hospital managers, administrative staff, nurses, and para-clinical staff participated in the survey. The main outcome measures were quality results, and the activities related to quality improvement include senior managers' commitment and support, strategic quality planning, education and training, rewards and recognition, quality management, use of data, the involvement of professionals in accreditation, and accreditation benefits. The questionnaire was applied using a 5-point Likert scale ranging from 1 “strongly disagree” to 5 “strongly agree”. One-way analysis of variance (ANOVA) was used to compare mean values between respondent groups. Results: Among nurses and managers, there was low support for accreditation and even less among para-clinical staff who fail to see accreditation having a positive impact on healthcare quality. Also, nurses' attitudes toward the accreditation benefits were more positive compared with the two other groups. Staff stated that the main reasons for low support were a lack of education and training to act upon the accreditation survey results and a lack of management visibility and support for quality improvement. Conclusion: Improving quality through means of hospital accreditation is a complex process with high demands for management and employees. Questionnaires on employees’ attitudes and perceptions of the impact of accreditation and quality improvement-related activities in the hospitals can provide valuable information on the current problems of a hospital accreditation program.