Equilibrium study on the mixed ligand complex formation of Fe-III with nitrilotriacetic acid and anthranilic acid diacetic acid (H3L) in the absence and in the presence of boric acid in different molar ratios provide the evidence of formation of Fe(L) Fe(OH)(-), Fe(L)(OH)(2)(2-), Fe(L)(H2BO4)(3-) and Fe-2(L)(2)(BO4)(5-) complexes in solution. Stability constants of the complexes and the complex formation equilibria in aqueous solution at 25 +/- 1degrees at a fixed ionic strength, I = 0.1 M (NaNO3) have been determined by potentiometric method.