In order to establish a tsunami alert system in New Caledonia in April 2008, the French Secretary of State for Overseas Affairs, with the aid of the UNESCO French Commission, mandated an investigation to build a more complete record of the most recent tsunamis. To complete this task, a call for witnesses was broadcast through various media and in public locations. These witnesses were then interviewed onsite about the phenomenon they had observed. Previous witness reports that had been obtained in the last few years were also used. For the most recent events, various archives were consulted. In total, 18 events were documented, of which 12 had not been previously mentioned in past work. These results confirm an exposure to a hazard of: (1) local origin (the southern part of the Vanuatu arc) with a very short post-seismic delay (< 30 min) before the arrival of wave trains; (2) regional origin (Solomon Islands arc, northern part of the Vanuatu arc) with a delay of several hours; and (3) an exposure to trans-oceanic tsunamis (Kamchatka 1952, South Chile 1960, Kuril Islands 2006, North Tonga 2009), unknown until today. These results highlight the necessity for New Caledonia to adopt an alert system, coupled with ocean tide gauges, that liaises with the main alert system for the Pacific (Pacific Tsunami Warning Center), and brings to light the importance of establishing a prevention campaign.