Purpose of present study is to risk assessment of fire and accidents using JSA method in Tehran FireDepartment, which was conducted as a case study in 7th Fire Department.Present research method is applied and descriptive-analytical due to its use in the fire department and interviews with experts.Importance conducting this study is to risk assessment in reducing financial and human losses of firefighters during fires and accidents.Statistical population was 600 experts, 235 from each organizational position according toCochran formula,through a risk assessment worksheet.Sampling method was simple and the sampling size was calculated as 148 people through Krejci and Morgan table.Validity of the questionnaire was approved by 20 experts in the field of safety and firefighting with the CVR index in the form of a Likert spectrum, and its value was calculated as 0.42. Reliability of the questionnaire was calculated in a test with 20 subjects using SPSS20 software with a Cronbach's alpha coefficient of 0.82. Findings from the risk assessment worksheets showed that risk of work at the operation site is for firefighters (5%), for assistants (28.57%),assistant commanders (29.5%),and commanders (20%).The risk during deployment to missions and station affairs for firefighters (84%), assistant (61.43%), assistant commander (43.2%), and commander (70%).The risk obtained in station affairs was obtained for firefighters (11%),assistant (10%), assistant commander (27.3%), and commander (10%).Results showed that the main reasons for the occurrence of occupational hazards are the large volume of work, carelessness of personnel, type of job and nature of the work of employees, and psychological effects.