The equilibrium and rate of solvent extraction of FeBr2 complexes from HBr solutions into benzene solutions of tributyl phosphate (TBP) have been investigated. It is found that two reactions control the iron(III)-TBP extraction from hydrobromic acid solutions. From HBr activity of 1.2–1.55 (molarity based) the reaction is inverse third order with respect to the aqueous phase acidity. From HBr activity of 1.7–6 (molarity based) the reaction is first order in HBr concentration in the aqueous phase. Both of these reactions are first order for both Fe(III) and TBP. The rate constants for these reactions were calculated and the rate-controlling steps are discussed.