Recent data (bathymetric map and petrological investigations) as well as reappraisal of local seismological events for more than 20 years allow us to present a new geodynamic interpretation of the southern New Hebrides subduction zone. A multidisciplinary approach to this complex area, where transform movements relay subduction process, clearly shows the interrelationships between intermediate seismicity, lithospheric plates tectonics and volcanic activity. According to our model, two hinge zones, tearing the downgoing slab along directions which parallel the convergence vector (N70" E), reasonably account for most seismological and petrological data from the region. The approach of the Loyalty islands ridge towards the trench and its increasing influence on the subduction regime is beginning to complicate this scheme.