This paper presents the environmental radioactivity concentrations in Tekirdag, a city in the region of Marmara in Turkey. Indoor and outdoor gamma-exposure rates were measured by Eberline smart portable counter, ESP-2. Gross alpha- and beta-counting of the water samples taken from municipal supplies, wells, and fountains were performed by using a gas-flow proportional counter, Berthold LB770-PC 10. Soil samples, collected from 40 different points in the area, were analyzed by using a gamma-ray spectrometry system connected with an HPGe detector and the radioactivity concentrations of the radio nuclides of uranium and thorium series (40)K and (137)Cs were determined. Dose and risk calculations were made. (c) 2004 Elsevier B.V. All rights reserved.