A new interesting category of polyconjugated polymer, poly(3,5-benzylidene)isopropylpiperidone, was obtained by condensation of isopropylpiperidone with terephthalaldehyde. Copolymerization and terpolymerization with cyclopentanone and/or cyclohexanone were also carried out. The model compound was prepared by the condensation of 2 mol benzaldehyde with isopropylpiperidone; the structure was elucidated by IR, H-1-NMR spectra, and elemental analyses. The polymers, copolymers, and terpolymers were characterized by elemental analyses, IR, H-1-NMR spectra, UV and visible spectra, viscometry, and X-ray analysis. The thermal behavior of the synthesized polymers was evaluated by TGA and DSC analyses and correlated with their structures. The morphology of terpolymer TV was examined by a scanning electron microscope. Electrical conductivities in the 10(-9)-10(-11) Omega(-1) cm(-1) range were observed: doping with iodine showed a small increase.