A recent suggestion that oxadiaziridine, N2H2O, might act as a potential high-energy density material prompts us to determine the enthalpies of formation and combustion of the two conformational isomers of this compound. As a fundamental measure of the reactivity of N2H2O, the proton affinity of both isomers was also determined. Gaussian-2, Gaussian-3, and two complete basis set methods were used.