The interaction of hydrogen with the stoichiometric ZnO(10 (1) over bar0) surface has been studied using ab initio, all-electron total energy calculations. A highly accurate hybrid density functional (B3LYP) implemented within a local Gaussian basis set has been employed. Details of the geometric and electronic structure of the surface have been determined. The results are discussed in terms of the role of this surface as a model system for both catalytic reactions and gas sensing applications. The Zn-O dimers on the (10 (1) over bar0) surface provide a. model system for the type I adsorption sites known to be important in surface mediated methanol synthesis reactions. The interaction of hydrogen with the Surface does not result in surface metallisation, and hence, the (10 (1) over bar0) surface is unlikely to be an active gas sensing material.