Ischia Island represents only the remnant of a once larger volcanic complex. To prove this hypothesis about 600 km of new marine geophysical data were analysed. Results reveal that the western offshore of the island consists of previously unreported E-W and NE-SW volcanic ridges that follow the regional structural patterns. The match between sea-borne magnetic anomalies and bathymetric/seismic data indicates the presence of a large, cooled magmatic system with deeper intrusions along the NE-SW direction. Some of the newly discovered submerged volcanoes are dissected by fault scarps that offset, with a strong vertical component, recentmost (possibly Holocene) marine and volcanoclastic deposits. Our data suggest the importance of regional tectonics (in particular along the NE-SW trend) on the patterns of magma uprising and on the recent local deformation in the Neapolitan volcanic district.