In this paper, the concentration of the activity of natural radionuclides is represented by 238U, 232Th and 40K. This concentration was measured by gamma spectroscopy, which was used to determine and calculate radioactive heat production for all radionuclides and their distribution pattern in the sediment samples from the Tigris River in Iraq. The results showed that the activity concentration of these radionuclides was within the allowed limits by the UNSCEAR. Field observations show that the sediments occurred due to the weathering of pre-existing sedimentary rocks that make up the area's geology. The estimated average radiogenic heat production rate was 0.3634 µW/m³. It ranged from 0.2430 to 0.6453 µW/m³, and within the internationally permissible limits, the radiogenic heat production rate in Tigris River sediments was low. It is recommended to conduct a comprehensive radiometric survey to cover all the areas through which the Tigris River passes in Iraq. It will help characterise the radiogenic heat produced for each geological area.