This paper presents a combined analysis of data collected both onshore and offshore in the epicentral region of the Mw 7.5, 26 November 1999, Ambrym earthquake. This offshore event occurred at the southern end of the back-arc thrust belt of the Vanuatu subduction zone, east of the island of Ambrym and resulted in permanent uplift of the eastern tip of the island. The data presented include (1) interpretation of older seismic lines across the tectonic front, (2) compilation of aftershock sequences, (3) postseismic bathymetry from multibeam surveys, (4) measurements of permanent coseismic ground motion using desiccated red algae, uplifted beaches, and uplifted coral colonies, and (5) dating of raised corals exposed along the coastal cliff. The active scarp of the main fault appears 13 km east of the eastern tip of Ambrym (40 km long, 2 km depth, 950 m maximum step). Uplift rates of 3.5--4 mm/yr for the past 8000 years are calculated by dating raised corals. This leads to a longer seismic recurrence interval of 375 years for events similar to that of 1999, assuming no interseismic subsidence. Postseismic ground motion was monitored using stainless steel marks set at three sites along the uplifted coast in January 2000. No significant motion could be recorded during the 2 years following the event, but slight subsidence cannot be ruled out. Finally, our results confirm that the back-arc belt of central Vanuatu is an active tectonic crustal wedge propagating eastward that accommodates more shortening than the Vanuatu subduction zone to the west.