The concentration of radium and radon has been determined in drinking water samples collected from various locations of Kutahya city, Turkey. The water samples are taken from public water sources and tap water, with the collector chamber method used to measure the radon and radium concentration. The radon concentration ranges between 0.1 and 48.61.7 Bq l(1), while the radium concentration varies from a minimum detectable activity of 0.020.70.2 Bq l(1) in Kutahya city. In addition to the radon and radium levels, parameters such as pH, conductivity and temperature of the water, humidity, pressure, elevation and the coordinates of the sampling points have also been measured and recorded. The annual effective dose from radon and radium due to typical water usage has been calculated. The resulting contribution to the annual effective dose due to radon ingestion varies between 0.3 and 124.2 Sv y(1); the contribution to the annual effective dose due to radium ingestion varies between 0 and 143.3 Sv y(1); the dose contribution to the stomach due to radon ingestion varies between 0.03 and 14.9 Sv y(1). The dose contribution due to radon inhalation ranges between 0.3 and 122.5 Sv y(1), assuming a typical transfer of radon in water to the air. For the overwhelming majority of the Kutahya population, it is determined that the average radiation exposure from drinking water is less than 73.6 Sv y(1).