AbstractSummary: Assemblies of oppositely charged L‐lysine/carboxylic acid functionalized polyphenylene dendrimers and hybrid multilayers of L‐lysine dendrimers/colloidal gold nanocrystals were fabricated as alternate multilayers on 3‐mercaptopropionic acid coated gold surfaces via layer‐by‐layer deposition. The fabrication of the multilayer films was monitored by kinetic and scan mode surface plasmon resonance spectroscopy. The permeability properties of the dendritic polyelectrolyte layers were characterized by electrochemistry in the presence of [Fe(CN)6]3−/4− as the redox couple. A high interfacial charge‐transfer resistance, originating from the electrostatic repulsion of the negatively charged redox couple against the negatively charged interface was observed and the charge‐transfer resistance found to increase with increasing number of layers.3D‐structure of the investigated polyphenylene dendrimers: a) G2(L‐lysine)8 and b) G2(COOH)16.magnified image3D‐structure of the investigated polyphenylene dendrimers: a) G2(L‐lysine)8 and b) G2(COOH)16.