The present study aimed to measure the radioactivity concentration of naturally occuring radionuclides in the locally used building materials from Kilpenthaur, Tiruvannmalai Dist, Tamilnadu, India. This study will also evaluate the radiation hazard arising due to the use of these materials in the construction of dwellings. The concentrations of natural radionuclides Ra-226, Th-232 and K-40 in five types of building materials have been measured by gamma spectrometry using NaI (Tl) 3 '' x 3 '' detector. The estimated radium equivalent activities (Ra-eq), indoor absorbed gamma dose rate (D-R), annual effective dose rate (H-R) and the external hazard indexes(H-ex) were lower than the recommended safe limit and are comparable with results from similar studies conducted in other countries. Therefore, the use of these building material samples under investigation in the construction of dwellings is considered to be safe for inhabitants.