Kinetic theory of Ostwald ripening was presented. Near equilibrium Ostwald ripening occured when larger clusters were grown at the expense of smaller clusters. A general population balance equation (PBE) for the cluster size distribution (CSD) was used to represent ripening kinetics for growth and dissolution. The effect of interfacial energy on solubility was represented in terms of the cluster radius by the Kelvin equation. A decline in the cluster number density and increase in the average cluster mass was observed.