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This paper summarizes the results of a reconnaissance seismic survey undertaken by the IFP-CEPM-ORSTOM group in 1972 in the young intra-oceanic arc of the New Hebrides. In the northern and southern segments this NNW-SSE trending arc the following structural zones can be recognized : a trench, an inner wall with one or two slope breaks and an intermediate basin between the upper slope break and the frontal arc, the frontal arc itself, a median sedimentary basin with a volcanic range located in its eastern part and finally a horst and graben province, which separates the North Fiji Plateau from the arc. This survey provided a more accurate definition of the frontal arc, a better description of the median sedimentary basin and led to the discovery of a strip characterized by magmatic intrusions, apparently related to transverse fracture zones. In the central segment, however, the features mentioned above are less evident. Here the position of the trench is occupied by the islands of Esperitu Santo and Malekula. The survey suggests that the two slope breaks on the inner wall of the northern trench continue into the western part of the Esperitu Santo Island. Also the median central basin is here replaced by the central basin. It is believed that the rectilinear nature of the northern New Hebrides is due to the presence of a recently arrived oceanic high at the subduction zone. In similar fashion the unusual central segment of the arc is related to the underthrusting of the complex E-W trending d'Entrecasteaux fracture zone and its associated high. This is supported by seismologic evidence given by Pascal (1974). The central basin is filled by two sequences, which are separated by an unconformity at its western edge. The maximum thickness exceeds 2,000 m in these sequences. The lower sedimentary sequence dates from the Middle to the uppermost Miocene, while the upper sequence includes the Plio-Pleistocene. The lower sequence can also be recognized in the median sedimentary basin to the North, suggesting a once continuous basin.