Taking advantage of the stability and penetrability of layer-by-layer (LbL) films, we develop a novel method to fabricate a branchlike structure of Ag aggregates on the matrix of a LbL polyelectrolyte multilayer by an electrodeposition technique. The morphology of Ag aggregates can be adjusted by electrodeposition time and potential. Moreover, after further chemisorption of a self-assembled monolayer of n-dodecanethiol, the as-prepared surface becomes superhydrophobic with a contact angle as high as 154 degrees and a tilt angle lower than 3 degrees.