In this paper, the natural radioactivity levels in a total of 117 samples of 14 different building materials collected from building construction sites and from the retailers in Adana were studied by means of gamma-ray spectrometer with HPGe detector. The mean activity concentrations of Ra-226, Th-232 and K-40 measured in the studied building material samples ranged from 2.1 to 88.2 Bq kg(-1), 1.8 to 52.7 Bq kg(-1) and 68.1 to 847.5 Bq kg(-1) for Ra-226, Th-232 and K-40 radionuclide, respectively. The external and internal index, the indoor absorbed dose rate and the corresponding annual effective dose were evaluated for potential exposure risks from the usage of the building material samples. The evaluated values of the external and internal index were below the recommended upper level. All the values of effective annual dose determined were lower than recommended exemption level of 0.3 mSv. The results suggest that the use of the studied building material samples in the construction of buildings is unlikely to give rise to any significant radiation exposure to the residents.