[en] Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of ²¹⁰Pb and ²¹⁰Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The ²¹⁰Pb was determined by counting the beta activity of the ²¹⁰Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0₄. The ²¹⁰Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for ²¹⁰Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for ²¹⁰Po. (author)