Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 36 3 2007 09 15 45 51 H Dargahi M Rezaiian 2015 10 03 Background: Quality assurance is implemented by the framework for the ISO 9001- 2000 " Quality Management Sys­tem "and ISO 15189: 2003. QA system will be more efficient if every organization's employees are commitment to QA im­plementation. This survey aimed to correlate between knowledge, attitude and performance of the employees with QA system implementation and its indicators observation in Tehran University of Medical Sciences Hospitals' Clinical Labo­ratories in 2003-2005. Methods: A Cross- sectional, descriptive analytical survey was accomplished with two types of questionnaires to col­lect Employees' demographic information and determine knowledge, attitude and performance of the employees about QA system and its indicators observation in TUMS Hospitals Laboratories. Also, a checklist including 685 questions pub­lished by WHO and ISO 15189: 2003 requirement series was made to monitor preanalytical, analytical, and postanalyti­cal stage of fourteen TUMS Hospitals' Clinical Laboratories. The data was saved by spss software and ana­lyzed by statistical method. Results: The results showed that knowledge, attitude and performance of the employees for implementation and ob-serva­tion of QA system and its indicators are more increased and positive with increased level of their academic de­grees. Conclusion: QA programs and indicators would be programmed if all of the employees participated to implement QA pro­grams in these laboratories. https://ijph.tums.ac.ir/index.php/ijph/article/view/2105 https://ijph.tums.ac.ir/index.php/ijph/article/download/2105/2086