An application of Evolution Strategies (ESs) to the structural identification of base isolation systems in earthquake engineering is presented. The analysis of a test problem considered in the literature clearly shows the effectiveness of ESs for the problem. Simple ESs outperform the previously used methods while state-of-theart ones, such as the CMA-ES, provide practically exact solutions. The application of the CMA-ES to the real data recorded in 2004, when releasing imposed displacements on a building in Solarino, leads to improved identification results and gives hints of limitations in the model available in literature. Improved models of higher dimensionality are introduced to overcome such limitations. The application of the CMA-ES with the new models leads to improvements of up to 53% compared to the previous solutions in literature. Thus, ESs are shown to be a very powerful tool for the dynamic identification of structural systems and an important aid in the design and evaluation of models of high dimensionality for structure identification.