This article examines the construction, operation and seismic performance of the El Torito tailings storage facility, Chile, under the 2015 Illapel earthquake. A two-dimensional plane strain finite-element model, employing coupled hydro-mechanical formulation, was developed to predict its response at these distinct stages. The tailings materials are simulated using a state parameter-based bounding surface plasticity model, while the remaining materials are simulated with a cyclic non-linear model. The computed seismic response of the tailings dam at the crest and the toe suggests satisfactory agreement with the monitoring data, predicting similar acceleration response spectra and spectral ratios for a wide range of periods. Limitations regarding the common lack of site-specific characterisation of tailings materials, particularly those in a decant pond, and the ensuing modelling assumptions, are also discussed. The results of this study demonstrate that advanced numerical modelling of tailings facilities to assess their safety is feasible and can be achieved if careful augmentation of the experimental data base, with studies available in the literature, is combined with appropriate engineering decisions to create a robust numerical model.