[en] The rate of the reaction of CH₃ and H has been measured at 300 K over the pressure range 50-1000 Torr with Ar and SF₆ as diluent gases. Flash photolysis of azomethane/ethylene mixtures was employed, coupled with gas chromatographic analysis and numerical simulation of the product yields. The rate data were compared with a RRKM analysis, using a minimum density of states criterion for locating the activated complex. The limiting high pressure rate constant so obtained is (1.5 +- 0.7) x 10^-10 cm³ molecule^-1s^-1. The RRKM model was found to give high temperature, high pressure rate constants for the dissociation of CH₄ which are significantly higher than those found experimentally. (orig.)