The Gediz River orginates at the Murat Mountain and is discharged to Aegean Sea near Foça. In this study, the level of natural radioactivity in the Gediz River basin has bcen investigated starting from the point at which the river joins the sea to source of the river. In the basin. 321 soil samples have been collected at l km intervals along the river. Further more gamma activity and radiometric uranium surveys have also been measured. The level of the natural radioactivity in soil samples has been determined using multichannel gamma analyser. The concentratİons of eU, eTh, %K, and gamma survey, radiometric uranium beta and gamma measurmcnts have been determined changing between of 0.10-7.54 ppm, 0.35-27.13 ppm, %0.04-3.19; 56-176 cps and 6-16 uR/h; 0-15 cps ve 0-24 cps, respectively.