A pseudo second-order kinetic expression was presented to explain the dissolution kinetics of solids in solution. The kinetic constant, initial dissolution rate, and theoretical saturation concentration according to pseudo second-order kinetic expression was defined. The proposed expression successfully represents the published dissolution kinetic profiles of alumina, digoxin, benzoic acid, lead chloride, and lecithin in solutions. A pseudo second-order kinetics based on fractional conversion successfully represents the dissolution kinetics of ulexite in ammonium acetate solutions. The pseudo second-order kinetics enabled the prediction of dissolution kinetics for higher residence time from experimental data obtained in relatively short time.