In this study, radioactive and heavy metal contaminations in sediments and waters of Bakırçay River in Western Turkey were investigated to determine their pollution potential. The radium concentrations in the water samples were measured using the collector-chamber method. The radioactivities of 40 K, 226 Ra and 232 Th in sediments and soils were found to be 45.30 to 839.19Bqkg −1 , 35.26 to 160.57Bqkg −1 and 1.86 to 131.49Bqkg −1 , respectively. The activity of 226 Ra in the water samples ranged from 0.09 to 0.36Bq/L. To determine the radiological hazard of natural radioactivity in the samples, the external terrestrial gamma dose rate in air (nGyh −1 ), annual effective dose rate (mSvy −1 ), radium equivalent activity (Bqkg −1 ) were calculated and compared with internationally recommended values.