This report presents the assessed thermochemical measurements on rubidium compounds upon which the property values, &Dgr;f H0, &Dgr;f G0,S0,C0p, andH0(T)−H0(0) at 298.15 K and &Dgr;f H0(0 K) recommended in the ‘‘NBS Tables of Chemical Thermodynamic Properties’’ are based. Included in this set of thermochemical measurements, or thermochemical reaction catalog, is a comparison of the observed values for the processes in question with those predicted (calculated) from the recommended property values in the forementioned tables. The evaluator’s initially assigned uncertainties on the experimental measurements and final estimated reliabilities on the recommended process values are given. This paper illustrates the evaluation procedure used in preparing the full set of recommended data in the ‘‘NBS Tables of Chemical Thermodynamic Properties’’.