This research looks into the behaviour of masonry infilled-frames (MIF) subjected to lateral loads. In most of the earthquake events, masonry has been blamed for the collapse of the buildings and to understand the interaction of the masonry and the frame members has become important. Initial research shows that despite having started the studies in the behaviour of MIF since the 1930s, researchers are far from being able to comprehensively predict the response of MIF when subjected to lateral loads. Therefore, the design codes are not able to provide appropriate analysis and design procedures. This PhD project aims to conduct extensive experimental and finite element modelling of MIF for structural engineers to rely focusing largely on typical Australian building construction systems.