We obtain exact analytic solution for the Green functions and survival probabilities of the reversible, geminate diffusion-influenced reaction AϩB↔CϩD in Laplace space, and in the time domain for various spatial dimensionalities. The asymptotic behavior ͑in one and three dimensions͒ goes as t Ϫ1/2 , like in the irreversible case, but approach to this limit may occur from either above or below. The implications of these results are demonstrated and discussed.