Methyl 3,4-di-(2'-hydroxyethoxy)benzylidenecyanoacetate 3 was prepared and condensed with 2,4-toluenediisocyanate and 3,3'-dimethoxy4,4'-biphenylenediisocyanate to yield polyurethanes 4 and 5 containing the NLO-phore dioxybenzylidenecyanoacetate group. The resulting polyurethanes 4-5 were soluble in common organic solvents. Polymers 4-5 showed a thermal stability up to 290degreesC in TGA thermograms with T. values in the range of 97-102degreesC in DSC thermograms. The SHG coefficients (d33) of poled polymer films were 4.7 x 10(-9) esti.