The activity concentrations of 222Rn with an AlphaGUARD system in well having different depths and in natural spring waters were measured to assess the natural radioactivity level of the Çorlu region. The measured concentrations varied from 22.04 to 63.92 Bq L−1 for 6 well water samples, 15.38–24.33 Bq L−1 for 6 spring water samples. The activity concentrations from 238U, 232Th and 40K in 11 soil samples collected from the same region were also determined and the outdoor gamma dose rates at 1 m above the surface at the same sampling points were measured. The results obtained in this study lie within safe limits recommended by WHO and UNSCEAR with the exception of the mean specific activity of 40K radionuclide.