The rate constant of the CH3O2 + NO gas-phase reaction was measured over the temperature range 199-429 K-using chemical ionization mass spectrometry detection of the CH3O2 reactant. The temperature-dependent expression for the rate constant was determined to be k(T) = (2.8 +/- 0.5) x 10(-12) exp{(285 +/- 60)/T} cm(3) molecule(-1) s(-1). The 298 K rate constant, k = (7.5 +/- 1.3) x 10(-12) cm(3) molecule(-1) s(-1), agrees well with previous results.