This is a preliminary report on alternating polyelectrolyte deposition (APD) with the goal of making electro-optic films at room temperature. By means of the APD method, films were built up layer-by-layer at room temperature by a dipping process. APD requires two complementary polymers, one being negatively charged and the other being positively charged. The polymer in solution is attracted to the solid substrate by coulombic forces to form the next layer on the substrate. For the first time, second-order nonlinear optical (NLO) polymer films were prepared by APD in which both polymers were NLO-active. The cationic polymer contained a side-chain stilbazole chromophore, and the anionic polymer contained a main-chain cinnamoyl chromophore. The intensity of the second harmonic signal generated in the film increased quadratically with each layer for the first twenty layers.