Communication: Living potassium poly(N,N-dimethylacrylamide) initiates the polymerization of styrene and butadiene, and adds 1,1-diphenylethylene in THF solution. The model compound alpha -potassio-N,N-dimethylpropionamide also polymerizes styrene and butadiene in contrast to esterenolates, which are known to be incapable of such reactions. The IR spectra and SEC traces of the polymers obtained unequivocally prove that styrene and butadiene initiation proceeds directly via the amidoenolate anion. Apparently, this is the first case observed where the polymerization of a nonpolar monomer can be initiated by the growing chain end of a polar polymer.