The province of Batman, located in southern Anatolia, has a population of approximately 500,000. To our knowledge, there exists no information regarding the environmental radioactivity in this province. Therefore, gamma activity measurements in soil, building materials and water samples and an indoor radon survey have been carried out in the Batman province. The mean activity concentrations of the natural radionuclides (Ra-226, Th-232 and K-40) and a fission product (Cs-137) were 35 +/- 8, 25 +/- 10, 274 +/- 167 and 12 +/- 7 Bq kg (-aEuro parts per thousand 1), respectively, in the soil samples. The concentrations of Ra-226, Th-232 and K-40 in the selected building materials ranged from 18 to 48 Bq kg (-aEuro parts per thousand 1), 8 to 49 Bq kg (-aEuro parts per thousand 1) and 68 to 477 Bq kg (-aEuro parts per thousand 1), respectively. All the calculated radium equivalent (Ra-eq) activity values of the building material samples are lower than the limit of 370 Bq kg (-aEuro parts per thousand 1), equivalent to a gamma-dose of 1.5 mSv year (-aEuro parts per thousand 1). The activity concentrations of Ra-226, Th-232 and K-40 in tap waters collected from the study area were determined with mean specific activity concentrations of 42 +/- 15, 35 +/- 9 and 524 +/- 190 mBq L (-aEuro parts per thousand 1), respectively. Indoor radon measurements were made at 95 dwellings in Batman using a CR-39 detector. The radon concentration levels were found to vary from 23 to 145 Bq m (-aEuro parts per thousand 3). The arithmetic mean of the measured radon concentration levels was found to be 84 Bq m (-aEuro parts per thousand 3) with a standard deviation value of 23 Bq m (-aEuro parts per thousand 3). The measurement results obtained in this study did not significantly differ from those taken in other parts of the country. The data generated in this study can be used to determine whether the Batman province is in a normal or high background radiation area and provides a valuable database for future estimations of the impact of radioactive pollution.