The literature on the reactions of carbon and metal oxides in a vacuum is reviewed and the results of an experimental study of the reduction of several metal oxides by carbon in a vacuum are reported. None of the refractory oxides studied were stable in contact with carbon in a vacuum at temperatures above 1380°C. Oxides of multivalent metals reacted at temperatures of 700°C. or less. As a method for producing pure metals, best results were obtained with chromium, vanadium, columbium, and tantalum. A chromium metal analyzing 97 per cent Cr and a vanadium metal analyzing 93 per cent V were obtained. It is concluded that the vacuum reduction method would be practical only for the production of the more expensive and rare metals.