The Mills-Nixon (MN) effect in trisannelated benzenes (1–10) is analyzed by Wiberg bond order (WBO), bond lengths alteration (ΔBL), Nucleus Independent Chemical (NICS), Harmonic Oscillator Model of Aromaticity (HOMA), and Localized orbital locator (LOL) analyses in B3LYP/6–311++G (d,p) level of theory. Coulomb repulsion, antiaromatic instability, angle strain and ring strain were the significant factors in the MN effect creation in the studied structures. The obtained results showed that the aromaticity is decreased in the benzene ring is in the 8 > 9 > 3 > 1 > 7 > 2 > 6 > 5 > 10 > 4 order and the strongest MN effect is seen in structure 4.