The available information, up to mid‐1972, for the rate constants of a series of gas phase chemical reactions has been evaluated critically. For each reaction, relevant thermodynamic data are presented and values for the equilibrium constant expressed in mathematical form. Kinetic data are presented in tabular and graphical form together with a discussion of the pertinent details. Recommended rate constant values are presented wherever possible with suggested error limits. The reactions considered involve the species H, O, C, N, S, OH, HS, S2, CS, SO, HSO2, NH2, NH3, NO, N2O, NO2, N2, O2, O4, N2, O2, O3, H2, H2O, SO2, SO3, CS2, OCS, H2S, and CO. Particular emphasis is given to reactions involving sulfur chemistry. The best available data for these reactions have been summarized in a table at the end of the paper. An appendix discussing the available evaluations and review articles published since 1960 also has been included to publicize these sources of either evaluated data or of extensive reference bibliographies.