The term "quarry products" comprises different natural rocks with different mineral contents, crushed into various sizes at quarries. The concentrations of the naturally occurring radionuclides 40 K, 238 U and 232 Th in quarry products from southwest Nigeria have been measured using gamma ray spectrometry. The gamma absorbed dose rate (D R), radium equivalent activity (Ra eq), annual effective dose (A d), activity concentration index (I), external radiation index (H ex) and internal radiation hazard index (H in) associated with the radionuclides are evaluated in order to assess the radiation hazard of quarry products used as building materials. The results showed that a few of the calculated radiological parameters are higher than permissible limit, hence, may pose a radiological hazard when used as building materials. All the radiological variables above were subjected to correlation analysis to determine the similarities and correlations among various samples. The data sets consist of 10 measured variables. The principal component Analysis (PCA) yields a two component representation of the acquired data, in which 93.3% of the total variance is explained.