In this study, iron(Ill) extraction from acidic chloride solutions using undiluted trihexyltetradecylphosphonium chloride (Cyphos IL 101) was carried out in a liquid-liquid extraction process. The extraction behaviors under various HCl, chloride, and iron(III) concentrations, selectivity; and extraction isotherm of iron(II) were investigated. It was found that iron(Ill) was extracted fast and efficiently it a wide chloride concentration range. The highly Selective separation of iron(III) from aluminum(III), calcium(1), magnesium(II), and potassium(I) in acidic chloride solutions was achieved with a separation factor of Fe(III) over Al(III) at 11 000 from a 3 M Ha solution. The maximum loading capacity of iron(III) reached 83.2 g.L-1 with a molar ratio of 0.91 for Fe(III)/Cyphos IL 101. Effective stripping of the loaded iron(II) was achieved with a 0.5 M H2SO4 solution. The iron-chloro complexes in both aqueous phase and Cyphos IL 101 phase were characterized using spectroscopic techniques. Ultraviolet-visible and Raman spectra confirmed that iron(III) formed a series of iron-chloro complexes in acidic chloride solutions, while present solely in the form of tetrachloroferrate complex ([FeCl4](-)) in the C-yphos IL 101 phase. An extraction mechanism was proposed in which both FeCl3 ion association and [FeCl4](-) anion exchange with the chloride anion of Cyphos IL 101 play the key role during iron(1.11) extraction.