This study investigates the displacement process of medium viscosity oil (10-100 cP) by aqueous solutions of associative polymers. Studies are conducted in two-dimensional etched-silicon micromodels under a reflected light microscope. The pore network pattern of the micromodel replicates Berea sandstone. Fluid advance is monitored at the pore level as well as over the entire micromodel.Associative polymers result in greater fluid viscosities at the same concentration as conventional polymers. Generally, we find that conventional polymers and brine result in severe fingering of the displacement fluid, however, associative polymers lead to more stable displacement characteristics at these concentrations.Experimental results show that associative polymers are a promising method to improve the displacement efficiency of viscous oils.