Numerical solutions are presented for the effect of radiation on mixed-convection flow of optically dense viscous fluids about an isothermal wedge embedded in a saturated porous medium. The partial differential equations are transformed into the nonsimilar boundary-layer equations, which are solved by the Keller box method. Numerical results for the dimensionless temperature profiles and the local Nusselt number parameter are presented for the combined convection parameter X, the wedge angle parameter A, the radiation-conduction parameter R d , and the surface temperature parameter H. The entire regime of the mixed convection is included, when X varies from 0 (pure free convection) to 1 (pure forced convection). As X varies from 0 to 1, the variation of the local Nusselt number parameter has the phenomenon of minimum. As the wedge angle parameter λ increases, the local Nusselt number parameter increases. When the radiation effect becomes significant (for the case of large values of R d and H), the local Nusselt number parameter is also greatly increased