The effect of polymer additives on extrusion slot coating was examined experimentally. Two polymer additives, i.e. carboxymethylcellulose (CMC) and polyacrylamide (PAA) powders, were added to Newtonian glycerin-water solutions for flow experiments. It was found that there exists an optimal concentration for each polymer additive in a coating solution, at which the maximum coating speed can be extended substantially. Adding polymers to coating solutions has little effect on the minimum wet thickness, and the minimum wet thickness is independent of the capillary number at relatively high coating speeds. The fluid elasticity tends to destroy the smooth coating and creates a coated film with an irregular surface.