Surface tension measurements were carried out to study the surface behavior of perfluorooctanoic acid (PFOA) in single-component systems, in the presence of silver ions, in two-component systems, and in three-component systems containing PFOA, silver ions and anisic acid anions. A cooperative adsorption of the silver ions and the surfactant was observed leading to decreases in the surface tension and in the surface excess of the surfactant. A hexagonal structural model is suggested to explain the results in a quantitative manner. Surface enrichment and depletion were noted in the three-component system, which depended on the relative strength of attraction between any two of the components. A comparison between PFOA and a commercial product FC143 was carried out. In general terms they behaved similarly.