In recent years, X–ray body scanners have been introduced at airports, penitentiaries and other places with considerable movement of people in order to combat drug trafficking, the entry of illegal materials and terrorism. However, although the application of this equipment in the national security area is indeed relevant, its use has caused a great deal of controversy, especially with regard to the doses absorbed and to the cancer induction risk associated with these exposures. The aim of this study is to use the Monte Carlo MCNPX code and the male adult voxel (MAX) and female adult voxel (FAX) phantoms, to evaluate the absorbed dose, effective dose and risk of cancer incidence attributable to exposures of individuals submitted to transmission X–ray body scanners in several projections. The effective dose values were calculated as recommended by the ICRP Publication 103 and the risk of cancer incidence were estimated through the BEIR VII Report.