AbstractPolymerization of 1‐(4‐pyridyl)‐1,3‐butadiene (PyBu) initiated by 2,2′‐azoisobutyronitrile (AIBN) or butyllithium (BuLi) was studied. Radical polymerization gave poly(PyBu) of low molecular weight, soluble in chloroform, tetrahydrofuran, or methanol. PyBu was polymerized by BuLi more rapidly than by AIBN, but the produced polyanion was not living. IR and1H NMR spectra of poly(PyBu) indicate the presence oftrans‐1,4‐andtrans‐3,4‐units. The content oftrans‐1,4‐units was found to be 75 mole‐% (for radical polymerization) or 90 mole‐% (for anionic polymerization). From radical copolymerization with styrene the following reactivity ratios resulted:r1(PyBu) = 7,21,r2(styrene) = 0,12;Q= 6, 1 ande= −0,42 (for PyBu). Reaction of PyBu with ethyl bromide in benzene at 30°C produced a polyelectrolyte, as observed