Mössbauer spectra of a series of the complexes of the type Na3[Fe/RCOO/6]xH2O /R=H, CH3, C2H5, C6H5/ has been recorded at 298±2 K. All display a quadrupole doublet with isomer shift and quadrupole splitting values in agreement with high spin iron/III/ octahedral geometry. The quadrupole splitting show an increasing trend with increasing polarizability of the substituent anion /RCOO–/. A linear correlation between quadrupole splitting values and the /Fe–O/ stretching frequencies has also been observed.