The infrared spectrum of poly(4-vinyl pyridine) was recorded in the range of 4000 cm−1to 400 cm−1. The vibrational assignments have been compared with those of polystyrene and its molecule's model: 1,3-diphenyl-propane and 4-(3-phenyl propyl) pyridine. The wavenumbers of the normal modev16bof the aromatic rings allowed us to establish the possible con-formers of this polymer. These results, are compared with those obtained from the1H-NMR spectroscopy for poly(4-vinyl pyridine) and polystyrene samples.