With 76 % of its 3063 native species of flora endemic, the New Caledonia biodiversity hotspot has long been recognized as having a high potential for conservation. Under the new IUCN Red List categories, 25 % of the endemic plants are at risk (Conservation Dependent, Vulnerable, Endangered, Critically Endangered), and five species are already extinct. A review of their distribution demonstrates that 83 % of the threatened species do not occur at all in a conservation area, and only 11 % have their conservation status improved by a protected area. The protected area network is geographically and floristically very unbalanced, with the rainforest and high altitude maquis in the south concentrating most of the conservation effort. Conversely, the middle and northern segments of the island, as well as all of the dry west coast, are left without adequate conservation area. Two vegetation types, the sclerophyll forest and the unique low/middle altitude maquis, are virtually totally unprotected. We conclude that the current network of protected areas needs to be considerably expanded, in terms of both geographical/floristic subregions within New Caledonia and vegetation type covered. With only 54 % of the conservation area covered by strict mining restrictions, existing reserves need to have their conservation efficiency improved by a more vigorous enforcement of their status, and by extending mining bans to all of them.