A constant heat rate thermogravimetric analysis was used to study the kinetics of the reaction ZnO(s) + Ti2O3(s) between 850 and 1400 K. Experiments were conducted with reactants of two particle size distributions and two molar ratios. The mole fraction equilibrium products were calculated and compared with experimental results. The rate of the reaction is described by an equation of the form : dalpha/dt = A exp(-E(a)/(RT)) (1 - alpha)n. For equal-molar reactants composed of ZnO(s) with a median particle diameter of 1 mum and Ti2O3 of 4 mum, n = 1, E(a) = 112 000 J/mol, and A = 90 1/s. The parameters depend on particle size. Products from the reaction are primarily Zn(g) and TiO2(s), but a side reaction between the product TiO2 and ZnO produces Zn2TiO4 and perhaps Zn2Ti3O8 and ZnTiO3. The amount of the titanate produced depends on the molar ratio of the reactants.