The present study analyses the data for occupational exposure to radiation in medical centres in Tehran, Iran, from film badge dosimetry data. The radiation workers belonged to three categories: diagnostic radiology (DR), radiotherapy (RT) and nuclear medicine (NM). For each category, the average effective doses during the years 2009 to 2011 were evaluated. Results show that occupational risk depended on job category. The highest exposure was recorded for NM workers and the lowest for RT ones. The annual average effective doses were found to be well below the permissible annual limit of 20 mSv with no over-exposure detected