In this work, the radionuclide activity concentrations of Ra-226, Th-232 and K-40 in surface soils and radon levels in dwellings of Karabuk, Turkey were determined in order to evaluate the environmental radioactivity. Concentrations of Ra-226, Th-232 and K-40 radionuclides were determined using gamma spectrometry with using HPGe detector. The etch track detectors (CR-39) were used to determine the distribution of radon concentrations. The average activity concentrations for Ra-226, Th-232 and K-40 were found as 21.0, 23.5 and 363.5 Bq kg(-1), respectively. The calculated average annual effective dose equivalent from the outdoor terrestrial gamma radiation from Ra-226, Th-232 and K-40 is 53.5 mu Sv y(-1). The average radon concentration and annual effective dose equivalent of Rn-222 in Karabuk dwellings were obtained 131.6 Bqm(-3) and 3.32 mSv y(-1), respectively. The evaluated data were compared with the data obtained from different countries.