In recent years, NQR is extensively studied with respect its potential applications in identification of illegal narcotic and counterfeit pharmaceutics. NQR has important advantages as a non-destructive, non-invasive, not-harmful method which is also sensitive to a crystal or molecular local symmetry. The aim of this work was to investigate N NQR spectra of some tetrazoles by the means of Density Functional Theory. It is known that tetrazole family is a class of nitrogen compounds that recently attracted much attention due to a broad range of potential applications, such as powerful explosives, solid rocket propellant fuels as well as novel biologically active substances. In this work, we analyze the results of DFT calculations and compare them the experimental NQR spectra to facilitate assignment of NQR lines. The latter is very important especially in the case of polymorphic structures.