Abstract The Schiff base N,N??(salicylidene)-methylenediamine, known as Salmen in combination with Cr(III) forms at pH = 4.5 a greenish precipitate, which is stable at room temperature but decomposed on heating. The study of the Infrared spectra, Electron Spin Resonance (ESR), X-ray diffraction and thermogravimetry has pointed out that the precipitation form is a complex, while the molar ratio showed that the combination rate of Cr(III): N,N?-bis(salicylidene)-methylenediamine is 1:1. The new complex crystallizes in the triclinic systems. This precipitation reaction can be used as a method for the gravimetric determination of Cr(III) with N,N?-bis(salicylidene)-methylenediamine, known as Salmen. The precipitate was dried in vacuum and weighed as C15H13O3N2Cr. The overage relative error is ? 0.33%. Salmen can be used in order to precipitate and to recover the chromium from wastewaters consequential to the tanning of natural fells.