Layer-by-layer (LbL) multilayer films of monomethyl maleate copolymers with styrene (P1) or vinyl carbazole (P2) were fabricated on oxidized surfaces, such as silicon wafers, quartz plates, or indium-tin oxide (ITO)-coated glass substrates, by using ethylenediamine as an interlayer cross-linking reagent. The polymer multilayers were easily converted to covalently laminated films by heat treatment, in which partially formed imide linkages interconnected the individual polymer layer. The polymer films formed on ITO electrodes effectively promote better contact between the electrodes and vapor-deposited N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine (TPD) films. Consequently, organic light-emitting diodes (OLEDs) of TPD/tris(8-quinolinolato)aluminum (Alq) revealed a large enhancement in hole injection and transport efficiency with the polymer films, compared to a bare ITO-based device. It is of particular interest that the OLED performances were monotonically improved with an increase in the number of layers for the P2 multilayers, sharply contrasting with the fact that the device responses got deteriorated with the multilayers (two or more layers) of P1. From the surface work function measurements, it was found that the modified ITO electrodes with P2 multilayers could effectively reduce the hole injection barrier at the ITO/TPD interfaces, unlike the case of the insulating P1 multilayers. Thus, the present study provides important insight for rational design of the better anode functionalization layers.