The rates of combination of Me. with NO and O2 were measured by flash spectroscopy at 295 DegK. The highpressure rate coeff. for Me. + NO(+M) -> MeNO(+M) was recorded as 1.0(+-0.15) * 1013 cm3 mole-1 sec-1. The low-pressure fall-off was interpreted with the Rice-Marcus model for D0(Me-NO) = 46.8kcal mole-1. The high-pressure rate coeff. for Me + O2(+M) -> MeO2(+M) was deduced to be .apprx.1.1 * 1012 cm3 mole-1 sec-1.