The estimation of solvation parameters for monatomic ions is reviewed and new values for the Gibbs energy, enthalpy, and entropy of solvation are given on the basis of the most recent thermodynamic data. The results for alkali metal and alkaline earth metal cations, and for the halide anions together with the sulfide anion, are examined within the context of a model based on the mean spherical approximation (MSA) for the Gibbs energy of ion-solvent interactions.