Expressions are given on cross-polarization resulting from the combined effects of rain and imperfect antenna isolations in satellite-to-earth links. The calculations at 4 and 11 GHz frequencies differ from previous work in two ways, namely, that the theory adopts a worst phase relationship between receiver and transmitter antennas in clear weather, and that a more realistic expression is used for the rain extent. Sample results are illustrated on cross polarization versus misalignment angle, clear weather antenna isolations, canting angle, attenuation, and rain rate.