There has been great concern about the health risks associated with the exposure due to the natural radioactivity present in coastal sediments all over the world. In this context, 35 beach and intertidal sediment samples were collected from north east coast of Tamilnadu, India, in order to evaluate their natural radioactivity. The activity concentrations of natural radionuclides such as 238U, 232Th and 40K in sediment samples were determined by gamma ray spectrometer and the mean values are compared with recommended and reported values. In order to evaluate the radiological hazard of the sediment, the absorbed dose rate, annual effective dose rate, hazard index, representative level index and excess lifetime cancer risk have been calculated and discussed. Average of all the calculated radiological parameters are within the recommended level for both beach and intertidal samples. However, some extreme values are also observed in Devanampattinam (S6) and Mahabalipuram (S22) beach due to the presence of black sands. No harmful radiation effects are pose to the public and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the area as a results of the activity of beach and intertidal sediments.