The catalytic reaction between acetone vapor and hydrogen on evaporated metallic catalysts in a static system has been followed by means of a Nier-type mass spectrometer. The main reaction observed on platinum, nickel, tungsten, iron, palladium, and gold was the formation of isopropanol but small amounts of propane were also formed simultaneously on platinum and, to a lesser extent, on the other metals with the exception of palladium and gold. Activation energies and frequency factors were measured for the production of isopropanol on all the metals and some pressure dependencies were obtained on nickel films. The order of activity of the metals was similar to the order for the hydrogenation of ethylene except for palladium, which was the least active of the five transition metals. A series of values for the equilibrium constant for the dehydrogenation of isopropanol to acetone was obtained at substantially lower temperatures than have been used in previous measurements.