Molecule and radical structures of Isobutyronitrile were studied by DFT computations. Results of conformational analysis performed by combination of molecular mechanic and B3LYP/6-311++G(d, p) methods showed that isobutyronitrile inelastic molecule which has only one conformer. Using this structure, radical structure was investigated. Possible radicals were modelled and the experimental Electron Paramagnetic Resonance parameters were calculated. The calculated parameters obtained from B3LYP/TZVP computations were compared with the experimental counterparts which were taken from literature. Determined Molecule and Radical structures were given in this study.