In this communication we report synthesis of three new donor-acceptor (DA) type conjugated polymers carrying 1,3,4-oxadiazole moiety and thiophene unit with different side groups at its 3,4 positions (4-methoxybenzyl:P1, 3-methylbenzyl:P2 and 4-nitrobenzyl:P3) through polycondensation route using a series of newly synthesized monomers. The structures of new monomers and polymers were confirmed by NMR, FTIR spectroscopic methods followed by elemental analysis. Further, molecular weight and thermal stability were determined using gel permeation chromatography and thermogravimetric analysis. The linear optical and electrochemical properties of polymers were investigated by UVvis absorption, fluorescence spectroscopic, and cyclic voltammetric studies. The polymers P1P3 were found to be thermally stable and their electrochemical band gaps were determined to be 1.98, 2.14, and 2.18 eV respectively. Further their nonlinear optical properties were investigated by Z-scan method using 532 nm, 7 ns laser pulses. The results reveal that they possess good optical limiting behavior due to effective three-photon absorption (3PA) with absorption coefficient 2.5 x 1024 m3W2, 1.6 x 1024 m3W2, and 1.0 x 1024 m3W2. POLYM. ENG. SCI., 2013. (c) 2013 Society of Plastics Engineers