A theoretical study was performed on the adsorption of some aliphatic aldehydes on a Zn 12O 12 nanocage, concerning energetic, geometric and electronic parameters using DFT at the B3LYP and M06-2X levels. Interaction of the aldehyde molecules with the surface was analyzed by means of DOS analysis and Bader’s method. It was expected that adsorption of the examined aldehydes on the ZnO nanocage would be achieved through the interaction of the carbonyl oxygen atom with the surface Zn 2+ ions. Effects of chain-length and steric congestions around the carbonyl group were inspected. The findings revealed that the adsorption energy was decreased on lengthening the aliphatic chain. Interactions between R–COH and Zn12 O12 induced significant changes in the HOMO–LUMO energy gap of the nanocage. Thus, the ZnO nanocage may be used as an aldehyde sensor device, especially for the detection of toxic formalde- hyde. Moreover, it was found that a V-doped nanocage can effectively interact with formaldehyde. It is believed that doping of ZnO with Ti and V effectively improves the sensitivity of the zinc oxide nanocage towards aliphatic aldehydes.