The reaction of CH2O with NO2 has been studied with a shock tube equipped with two stabilized ew CO lasers. The production of CO, NO, and H2O has been monitored with the CO lasers in the temperature range of 1140–1650 K using three different Ar‐diluted CH2O‐NO2 mixtures. Kinetic modeling and sensitivity analysis of the observed CO, NO, and H2O production profiles over the entire range of reaction conditions employed indicate that the bimolecular metathetical reaction, NO2 + CH2O → HONO + CHO (1) affects most strongly the yields of these products. Combination of the kinetically modeled values of 퓀1 with those obtained recently from a low temperature pyrolytic study, ref. , leads to (Formula Presented.) for the broad temperature range of 300–2000 K.