Aqueous biphasic systems (ABSs) based on alcohol-salt are of significant interest because of their low cost and environmental impact, as well as their higher selectivity and fast phase segregation, when compared to a polymer salt ABS. The salt effect was evaluated in ethanol-based aqueous biphasic systems using five different salts (NaH2PO4, K2HPO4, K3PO4, K2CO3, or K3C6H5O7) at 298.15 K and atmospheric pressure. The results suggest that both the cation and anion natures present an influence on liquid-liquid equilibrium (LLE). To describe the experimental LLE data, the nonrandom two liquid model was used to adjust the experimental data, which showed a good fit (rmsd < 0.68%). The salt influence in ABSs and its partition ability was accounted by phase diagrams, as well as a partition study using nicotine and caffeine. Results have shown high partition yield and high selectivity.