[en] Gamma radiation assisted changes in stability and optical properties of CdTe colloidal quantum dots (QD) capped with 3-mercaptopropionic acid (MPA) molecules have been reported in this article. Synthesized QDs in water, using hydrothermal method, have been exposed to different gamma doses to see the changes in their light absorption and emission properties of QDs. Colour of light absorption and emissions are blue shifted for lower pH conditions followed by precipitation (after few days) of the whole dissolved materials as a response to irradiation due to photo-oxidation. Surprisingly, redshift has been observed for the same gamma doses when pH of QDs solution raised to higher number which also results in improved stability of QDs to with stand against irradiation (compared to acidic pH environment). Therefore, the solution of QDs with higher pH value is stable for future useful modifications of QD structures using radiation. These modifications may include the growth of single or multishells over core QDs by using this irradiation method to enhance their stability and optical properties. (author)