Formulas for the scattering from an inhomogeneous sphere in a fluid‐saturated porous medium are used to construct a self‐consistent effective medium approximation for the coefficients in Biot’s equations of poroelasticity [J. Acoust. Soc. Am.28, 168 (1956)] when the material constituting the porous solid frame is not homogeneous on the microscopic scale. The discussion is restricted to porous materials exhibiting both macroscopic and microscopic isotropy. Brown and Korringa [Geophysics40, 608 (1975)] have previously found the general form of these coefficients. The present results give explicit estimates of all the coefficients in terms of the moduli of the solid constituents. The results are also shown to be completely consistent with the well‐known results of Gassmann and of Biot and Willis, as well as those of Brown and Korringa.