We investigated the nonlinear optical (NLO) properties of two newly synthesized conjugated polymers P1 and P2 carrying 1,3,4-oxadiazole, 3,4-dibenzyloxythiophene, and 3,4-dialkoxythiophene moieties along the main chain, as potential NLO active materials. Their structures have been well characterized. The nonlinear measurements were performed by Z-scan using 532 nm, 7 ns laser pulses. Calculated values of figure of merit and beta follow the criteria for good NLO materials. These results suggest that polymers are promising materials for applications in photonics.