Decomposition of the CF3CFHO radical formed in the reaction of CF3CFHO2 radicals with NO was studied at 296 and 393 K using a pulse radiolysis transient VIS‐UV absorption absolute rate technique. At room temperature in 1 atmosphere of SF6 diluent it was found that the majority (79 ± 20)% of CF3CFHO radicals formed in the CF3CFHO2 + NO reaction decompose within 3 μs via C(SINGLE BOND)C bond scission. This result is discussed with respect to the current understanding of the atmospheric degradation of HFC‐134a. As a part of the present work the rate constant ratio kCF3CFH+02/kCF3CFH+NO was determined to be 0.144 ± 0.029 in one atmosphere of SF6 diluent at 296 K. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 209–217, 1997.