[en] The walls of a fluoroscopy room must be shielded to prevent unnecessary exposures to technicians and public individuals. Thus this dissertation aims to describe the methodologies contained in two documents which are references for the calculation of shielding those rooms. They are the National Council on Radiation Protection and Measurements Report No. 49 (NCRP Report No. 49) and No. 147 (NCRP Report No. 147), the latter being more recent publication. And based on such description was made a comparative study between the two methodologies, using for this, as a benchmark, spreadsheets computer program developed by Wolfram Mathematica 6. With that we could reach the final thickness of the barriers to a Standard Plan for a fluoroscopy room (provided by Siemens) and noted that the NCRP-49 presents a methodology with results more conservative. (author)