Nowadays, there is still very little scientific understanding of the seismic response of mixed masonry-r.c. structures, despite their unneglectable frequency, in particular in public building assets. This contribution presents the investigations carried out on a representative school, built at the turn of 1950s and 1960s. It is a two-storey building, characterised by central longitudinal load-bearing masonry walls, as well as transverse masonry panels, coupled with r.c. frames on major façades, and isolated columns in halls. This structural configuration is commonly found in public buildings, specifically schools. R.c. elements were exploited to build open-space environments, as well as to increase openings on façades, thus ensuring a better natural lighting.In this study, masonry components were modelled through an equivalent frame model (EFM). Half-height infills, interacting with frames, were simulated through a single-strut macro-model. To simulate the nonlinear response of the structure, lumped plasticity hinges were implemented for both load-bearing masonry and infills, while a fibre model was chosen for r.c. frames. The presence of non-seismic joints among structural units was also considered. The relative contribution of masonry and r.c. components was investigated through parametric linear dynamic analyses. Preliminary nonlinear static analyses (NLSA) were carried out to identify thresholds of damage. Moreover, the structure was analysed through nonlinear time history analyses (NLTHA) by applying a large number of natural unscaled ground motion records. Lastly, fragility curves were estimated from outcomes of NLTHA. The derived fragility model represents a key instrument in seismic risk evaluations for the analysed macro-class, being one of the few examples of fragility sets specific for mixed masonry-r.c. buildings.