<p>The distribution of the radiological characteristics of the natural radioisotopes ⁴⁰&#xa0;K, ²³²Th, and ²²⁶Ra in the Upper Cretaceous-Lower Paleogene sedimentary rock samples collected from Wadi Queih area, Red Sea, Egypt, was measured using gamma-ray spectrometer with an NaI(Tl) detector. The sedimentary sequence under study was divided into four groups (A, B, C, D) according to the lithological variations and dominant rock type. The average activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰&#xa0;K were 309.11 ± 15.49, 336.91 ± 16.62 and 887.58 ± 44.38&#xa0;Bq/kg for group (A); 240.95 ± 12.06, 396.49 ± 19.83 and 570.49 ± 31.93&#xa0;Bq/kg for group (B); 260.21 ± 13.03, 333.49 ± 16.68 and 568.54 ± 28.43&#xa0;Bq/kg for group (C); and 238.56 ± 11.93, 369.62 ± 18.75 and 633.32 ± 32.74&#xa0;Bq/kg for group (D), respectively. For ²²⁶Ra, ²³²Th, and ⁴⁰&#xa0;K, the average activity concentrations in each of the four groups are higher than the UNSCEAR worldwide average values of 35, 30 and 400&#xa0;Bq/kg, respectively. The radiological hazard parameters that were used to evaluate the radiation hazards associated with the rock samples, the calculated values of these indices exceed internationally recommended limits in several cases, indicating a non-negligible radiological risk in some rock units, particularly phosphate-rich and cherty lithologies. These findings highlight the need for radiological safety assessments in regions where such rocks are used in construction or agriculture. Given the radiological threat to residents and the need for radiation protection precautions, the collected data offer a useful future database for estimating the impact of radioactive contamination in the studied area as well as in locations where the rocks are used as building materials or in agricultural reclamations. The results also offer baseline reference values that can support future environmental monitoring, land-use planning, and radiation protection policy.</p>