Abstract: A tertiary butyl hydroperoxide feedstock, such as one prepared from the reaction product formed by the reaction of isobutane with molecular oxygen and which feedstock comprises tertiary butyl hydroperoxide dissolved in tertiary butyl alcohol, is charged to a catalytic decomposition zone where the tertiary butyl hydroperoxide is catalytically decomposed in the presence of a soluble catalyst system to provide a decomposition reaction product characterized by a high conversion rate and a high selectivity of tertiary butyl hydroperoxide to tertiary butyl alcohol, the catalyst system being composed of a soluble iron compound and a soluble ruthenium compound.