The generality of the formation of an N,O-diacylhydroxylamine from the oxidation of hydroxamic acids in an inert solvent is confirmed for an extended range of oxidizing agents. Oxidation of o-alkylhydroxamic acids with a variety of oxidizing agents yields an ester and small amounts of the corresponding carboxylic acid. No evidence was obtained for an oxidative intramolecular cyclization of an O-alkyl-hydroxamic acid, in cases where this was possible, either in the presence or absence of ultraviolet irradiation.