The effect of precoating of silica with polyamine surfactants on the adsorption of five model compounds containing asphalt-like functionalities was studied. Hexadecyltrimethylammonium chloride (HDTMA) and 1-hexadecylamine were used for silica precoating. The model compounds representing five asphalt functionalities were benzoic acid, phenol, benzylbenzoate, benzophenone, and quinoline. All the adsorption isotherms conformed well to the Langmuir adsorption model. All the model compounds showed decreased adsorption with the HDTMA precoating. However, two acidic compounds, benzoic acid and phenol, showed enhanced adsorption on the silica precoated with 1-hexadecylamine. In aqueous solutions, the adsorption of the acidic compounds were in the following order: silica precoated with 1-hexadecylamine > silica precoated with HDTMA > uncoated silica.