The present work deals with geology, mineralization and spectrometric prospecting of the granitic rocks associated with pegmatites G. El Fereyid - W. Rahaba area, South Eastern Desert of Egypt. The granitic rocks comprise tonalite, monzogranite and pegmatite occur as a vein type (granitic and perthitic pegmatites) hosted within the monzogranite. Pegmatitic bodies associating the monzogranite contains radioactive minerals such as thorite, uranothorite, samarskite, ishikawaite, and fergusonite, besides the presence of some radioelements-bearing accessory minerals such as; zircon, monazite and fluorite. The high level of radioactivity in pegmatites is attributed to the presence of the radioactive minerals thorite and uranothorite as confirmed by ESME analysis. The uranium and thorium mineralization in the radioactive pegmatite could be regarded as magmatic (syngenetic) as well as hydrothermal (epigenetic). From the D-factor of the monzogranite and pegmatite veins of the G. El Fereyid - W. Rahaba area, it is clear that chemical uranium is more than the radiometric uranium in all of the samples, which reflects disequilibrium due to the addition of uranium. This means that uranium has been transported recently and has not time for decay.