Cadmium oxide (CdO) quantum dots were synthesized in the laboratory by quenching method using CdO powder sintered at 9000C and ethyl alcohol kept at ice cold temperature. X-ray diffraction investigations reveal the NaCl cubic structure of CdO quantum dots. Addition of ethylenediamine to a portion of reaction mixture containing quantum dots results in the conversion of nanoparticles to nanorods. Heavy ion irradiation using 90 MeV Carbon (C+6) ion beam accelerated at 15 UD Pelletron, with fluence varying from 1011 to 1013 ions/cm2 , produced enlargement in the size of quantum dots revealed by TEM investigations. Heavy ion irradiation effects need to be investigated further, in view of industrial applications of quantum dots.