The kinetics of the reaction of hydroxyl radicals with trifluoroiodomethane were investigated by the flash photolysis-resonance fluorescence technique. A rate constant of k = 5.8 x 10(-12) exp((-11,3 kJ mol(-1))/RT) cm(3) molecule(-1) s(-1) was measured over the temperature range 280-450 K with accuracy limits of 20% (450 K) to 30% (280 K). Different product channels were investigated by ab initio methods, and the dominant products are CF3 + HOI. The enthalpy of formation of hypoiodous acid was＇ analyzed with Gaussian-2 theory, in conjunction with G2 energies for INO, ICN, ClCN, and other species. The transition state and reaction coordinate for OH + CF3I was characterized at the G2(MP2) level, and the results suggest a negligible barrier to the reverse reaction of CF3 + HOI, so that the measured forward activation energy can be used to derive Delta(f)H(298)(HOI) = -69.6 +/- 5.4 kJ mol(-1). The implications of the kinetics and thermochemistry for iodine chemistry in flames and the atmosphere are discussed, and for the range 280-2000 K a proposed rate expression is k = 2.9 x 10(-16)(T/K)(1.5) exp(-(960 K)/T) cm(3) molecule(-1) s(-1).