A scanning probe microscopy investigation of the self‐organization and local electronic properties of spin‐coated ultrathin films of N‐alkyl substituted perylenetetracarboxdiimide (PDI) is described. By carefully balancing the interplay between molecule–molecule and molecule–substrate interactions, PDI is able to form highly ordered supramolecular architectures on flat surfaces from solution. On an electrically insulating yet highly polar surface (mica) PDI forms strongly anisotropic architectures with needlelike structures with lengths of up to a few micrometers. On a conductive yet apolar surface (highly oriented pyrolytic graphite), the competition between the strong molecule–substrate interactions and the intermolecular forces leads to the generation of more disordered structures. The local electronic properties of these architectures are studied by Kelvin probe force microscopy by estimating their surface potential …