The city of Ordu is in the Eastern Black Sea region of Turkey with a population of approximately 716,000. Presently there is no information available about radioactivity levels in Ordu soil and building materials. For this reason, activity concentrations in soil and building material samples collected from different sampling stations in Ordu were measured using gamma-ray spectrometry. In addition to natural radionuclides, Cs-137 was detected in the soil samples and the possible origins of this radionuclide were discussed. The activity concentrations of soil samples ranged from 13.4 to 151.7 Bq kg(-1) for Ra-226, from 14.3 to 98.5 Bq kg(-1) for Th-232, from 303 to 1107 Bq kg(-1) for K-40 and from 67.4 to 275.3 Bq kg(-1) for Cs-137. The mean concentrations of Ra-226, Th-232 and K-40 in selected building materials were 34.5, 26.9 and 378.4 Bq kg(-1), respectively. The results were compared with the reported data from different works. From the measurements, radium equivalent activity, terrestrial absorbed dose, annual effective dose rate, external hazard indices and internal hazard indices were calculated, and were found to be within the acceptable limits. The data presented in this study might be useful as a baseline data for future estimations of a population's exposure.