The reaction between nitric oxide and vibrationally excited ozone was studied in a fast flow reactor by monitoring the visible emission from electronically excited NO2*. The antisymmetric mode (ν3) of O3 was excited with a Q-switched 9.6 μm CO2 laser, and a laser-induced signal was detected, with a rise rate constant of (4.0 ± 0.5) × 1011 cm3/mole sec and a decay rate constant of (1.1 ± 0.1) × 1011 cm3/mole sec for an NO-rich mixture. The latter was unaffected by addition of large amounts of He or Ar, indicating that the signal was not a thermal effect. Most of the measurements were made at 350°K; however, the He and Ar dilution results suggest that the enhanced reaction rate is not very sensitive to temperature. In order to explain the observed rise times, it was necessary to postulate an intermediate step prior to the chemical reaction. A model which is consistent with our data has energy transferred from ν3 to ν2 (the bending mode) at a rate of (2.9 ± 0.5) × 1011 cm3/mole sec for NO and a rate of (1.1 ± 0.2) × 1011 cm3/mole sec for He. According to this model, the rate constant for the reaction of NO with O3 (ν2= 1) producing vibrationally excited ground state NO2†, NO + O3† (010) 3 NO2† + O2 is (1.5 ± 0.2) × 1011 cm3/mole sec, and the relative rate for the reaction of O3 (ν2 = 1) and O3(ν2 = 0) with NO was estimated to be k3(1) k3(0) ≈ 22.