Two perylenediimide (PDI) regioisomers with the central core substituted at the ortho (Y-αPDI) and bay (Y-βPDI) areas of the PDIs were successfully prepared. The regioisomeric effects on the physicochemical and charge-transport properties were thoroughly investigated. The results unravel that Y-βPDI shows ambipolar transport with higher mobilities compared to its α -counterpart, which is due to its favourable molecular geometry, stronger intermolecular interaction and improved electron-withdrawing ability.