A model diet for an Aboriginal adult living entirely on bush foods collected from the Alligator Rivers Region of the Northern Territory has been established. Results of investigations of the specific activities of thorium-230, radium-226, lead-210 and polonium-210 in 123 samples of bush foods collected by Ranger Uranium Mines Pty. Ltd. during pre-production and production periods are presented. For all the investigated bush food items, excluding freshwater mussels (Velesunio angasi), no systematic differences were found between the specific activities of the radionuclides monitored in food items sampled during preproduction and production periods. Preliminary estimates of annual effective dose equivalent (DE) rates for stochastic effects on an adult living entirely on the model bush diet are presented. Of the four radionuclides monitored the major contributor to the effective DE rates appears to be lead-210 followed by radium-226. Among the selected nine components of the diet the major contributor to the effective DE rates appear to be mussels, water lilies and fish.