[en] γ-radiolysis of aqueous solutions of pure dichromate and dichromate/formate mixture have been studied at neutral pH. In the presence of the ions the G[-Cr(VI)] is higher than in pure dichromate solution. The variation of the G[-Cr(VI)] with the concentrations of the formate and dichromate ions, as well as with dose have been studied. Cr(VI) was quantitatively reduced to Cr(III) in pure as well as in mixed solutions. Solutions were irradiated with γ-rays from a 2 kCi source of Co-60 at a dose rate of 5.2 krad/min without removing dissolved oxygen. The irradiated solution was centrifuged, acidified with H₂SO₄ and the concentration of the residual Cr(VI) was measured spectrophotometrically at 440 nm. (T.I.)