This masonry research investigated the structural response of masonry wall panels when subjected to static lateral loads. The lateral load capacity and deformational characteristics of two full-scale wall panels, constructed with dense concrete blocks and laid in thin joint mortar of 3 mm thickness, have been studied experimentally and with numerical models. Linear elastic equations have been employed to predict the distribution of moments and failure load of the panels. The necessary material properties were determined from a series of small scale tests involving a total of 24 wallettes. The wallettes were built and tested in accordance with the British Standards recommendations as outlined in BS 5628: Part 1. and complied with the European code, EN 1996-1-1. The research found that, when subjected to lateral loads, concrete block masonry built using thin layer mortar behaves as a homogeneous elastic plate and fail in a brittle manner. Recommendations on the application of elastic theory concepts as the basis for development of material constitutive laws have been made based on the fact that linear elastic equations have been tested against experimental data and found to be valid.