Natural radioactivity due to 238U, 232Th, and 40K in brick samples from Tamil Nadu was determined using gamma-ray spectrometry. The calculated mean activity concentrations of 238U, 232Th, and 40K, 69 ± 6, 62 ± 6, and 462 ± 23 Bq kg− 1, are higher than the world recommended limits of 35, 45, and 420 Bq kg− 1, respectively, and they are compared with the other countries. The calculated radiological parameters radium equivalent activity (193 ± 17 Bq kg− 1), internal hazard index (0.71 ± 0.06), activity utilization index (1.43 ± 0.13) were lower, while absorbed dose rate (89 ± 8 nGy h− 1), annual effective dose equivalent (0.43 ± 0.04 mSv y− 1) and excess lifetime cancer risk (1.52 ± 0.13 mSv y− 1), which are slightly higher than the world’s recommended limits. The minerals presented in the soil samples were identified using FT-IR and XRD techniques. Both techniques revealed that the presence of quartz, orthoclase, kaolinite, microcline, albite, illite, calcite, montmorillonite and organic carbon in the samples. Bi-variate statistical analysis was estimated to corroborate the relationship between radionuclides and radiological hazards.