5,10,15,26=Tetrakis(4,aininophenyl)porphyrin (TAPP) undergoes,oxidatiVe polymerizatiOn to form electronically-conductive, nanofibrous structures in which the porphyrin units are linked by phenazine bridges:PolymerizationS by Chemical oxidation, electrochemical oxidation; and interfacial Oxidative polymerization are described. Poly-TAPP (pTAPP) films have been characterized using scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy), and UV-vis spectroscopy. The polymer morphology is consistently nanofibrous, with some differences depending on the specific synthetic method. The polymer films show distinctive electrochromism at different redox and protonation states: A Pourbaix diagram correlates the proposed redox and protonation state S of the polymer-with applied potential, pH, and perceived color of the film. pTAPP shows the lowest resistance to oxidative doping/dedoping at low pH and potentials between +0.4 and +0.5 V vs Ag/AgCl.