The effect of γ-irradiation on thermophoto-emf of hot carriers in n-Cd0.94Hg0.06Тe and р-Cd0.82Hg0.18Тe single crystals has been studied. The dependence of the pattern of |Utp| curves on E in the test CdxHg1—хTe crystals is explained by the change in the degree of spatial heterogeneity of these crystals resulted from the accumulation of point radiation defects at relatively low Dγ and their spatial ordering caused by the introduction of a large number of point radiation defects at higher exposures. The proposed mechanism for the effect of γ-irradiation on the thermophoto-emf of hot carriers explains satisfactorily the dependence of |Utp| kinetics on radiation dose, sample composition, temperature, and field strength.