The present topical volume presents a collection of contributions from a workshop that took place in Madrid in February 2014. Earthquake Early Warning System (EEWS) are a rather recent development in seismology that allows issue warnings to a site with a short lead-time about the impending arrival of the largest strong ground motion from an earthquake, after the first wave arrivals have been detected nearer to the source by adequate sensors. The Ibero-Mahgrebian region, containing Portugal, Spain, Morocco, Algeria and Tunisia, is subject to the occurrence of large earthquakes that may be followed by large tsunamis, as was the case of the Lisbon earthquake of 1755.