The tin(II) halides are important in a number of industrial processes and technological devices, for example, in the chemical vapor deposition of tin(IV) oxide films for the semiconductor industry, in the production of catalysts, and as a method of refining the spectral output of high intensity discharge lamps. Modeling of such processes requires databases of reliable, self-consistent thermochemical parameters. A survey of the physicochemical properties and appropriate standard thermochemical data has been made for the tin(II) halides, SnXX' (X, X' = Cl, Br, I), and a self-consistent set of thermochemical parameters are selected for the solid, liquid, and gas phases of these materials. In a few cases where data are simply unavailable, data are derived using a variety of estimation techniques. The benchmark employed to select the parameters in this work is that they accurately predict experimental vapor pressures where these are available. Finally, estimation techniques (Supporting Information) are used to provide supporting evidence as to the correctness of the magnitudes of data selected using the benchmark.