Abstract: Di-substituted silanetellurones, X₂Si=Te (X=H, F, Cl, Br, I and CN) are the target of this research. They are organometallic analogues, also known as heavy ketones, and they have recently been of great interest to researchers. Knowledge of the properties of such heavy ketones is important for a better understanding of both the chalcogen and substituent effects. The chemistry of multi-bonded compounds between group 14 and heavier chalcogen atoms has attracted chemists in various fields, as these molecules have proven to be convenient models for studying fundamental chemical problems and valuable intermediate products in synthesis. However, the literature of the mentioned species is limited and this research work endeavors a systematic investigation of these silanetellurones, using theoretical methods. We report the structural and spectroscopic parameters as well as the ionization potentials (IP_ad and IP_ad(ZPVE)), the neutral–anion separations (EA_ad and EA_ad(ZPVE)), the singlet–triplet splittings, the Kohn-Sham HOMO–LUMO gaps besides the nucleophilicity (N) and global electrophilicity (ω) indices. Since experimental data are still lacking for silanetellurones, the findings of this work would add to the literature, assist experimentalists to generate and further explore these novel species as well as rationalize some reactions pertaining to silanetellurones.