en پژوهشي Original Research Articles <p style="text-align: justify;"><strong>Objectives:</strong> Behavioral-based safety is a term used to describe the prevention of accidents, injuries and loss in the workplace. An effective behavior-based safety program relies on engaging employees to understand how unsafe behaviors lead to injuries and how to eliminate them from the workplace. This paper examines behavior-based safety program in a massive construction site.</p> <p style="text-align: justify;"><strong>Methods:</strong> For this purpose experiment and control groups were selected and performance feedback of workers about unsafe and critical behaviors has been reviewed.</p> <p style="text-align: justify;"><strong>Results:</strong> Test results show that among the critical behaviors, using ladder correctly among the workers had good feedback, but there is still a problem in concrete pouring behavior. Safety performance index of the experimental group has changed from 66% to 92%.</p> <p style="text-align: justify;"><strong>Discussion:</strong> Behavioral-based safety, an approach of identifying and preventing accidents, has many advantages. Implementing behavioral-based safety practices in the workplace ensures a protected environment. Observations identify which behaviors may be unsafe therefore the best practices may be developed.</p> Construction site, Critical behavior, Behavior-based safety 21 25 http://irj.uswr.ac.ir/browse.php?a_code=A-10-1-68&slc_lang=en&sid=1 Morteza Oostakhan morteza_avesta@yahoo.com Yes Department of Occupational Health Engineering, Faculty of Medicine, Tarbiat Modares University, Tehran, Iran. Amirabbas Mofidi No Department of Occupational Health Engineering, Faculty of Medicine, Tarbiat Modares University, Tehran, Iran. Amirhosain Davudian Talab No Department of Ergonomics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.