A review of our present knowledge concerning the solvation of excess electrons e−exc → e−solvproduced by photoionization or radiolysis in polar media has been attempted. Various properties of the solvated electron (proposed solvation mechanisms, structure, physicochemical characteristics) are considered. In spite of some similarities, e−solvdoes not seem to be a good prototype for solvated halide anions. The behavior of e−excin heterogeneous model systems, such as micellar solutions and molecular clusters, is described and correlated with that observed in homogeneous media.Keywords: excess electrons, homogeneous and heterogeneous polar media, photoionization, radiolysis, solvation, charge transfer to solvent, properties of the solvated electron, micellar solutions, molecular clusters, comparison with the solvation of anions.