ABSTRACT In this paper, a continuum 3D finite-element model is presented to determine the seismic behaviour of masonry cross vaults under seismic motions. The work regards the investigation of a regular cross vault made of clay bricks and hydraulic mortar, accounting for two distinct configurations: an un-strengthened design and one strengthened through the application of a fibre-based reinforcement. The research adopts parts of the blind prediction simulation developed during the SERA project. For both configurations, the manuscript follows two main steps: a prediction simulation, based on laboratory tests executed on specimens made with the same materials of the cross vault, and a post-diction calibration, based on the outcomes of the experimental tests on the full-scale model. The final FE models, realized through the commercial software ABAQUS CAE, have allowed a satisfactory simulation of the experiment, providing insights for the modelling of these structural systems through continuum approaches.