In many Oceanic languages a category of plain verbs expressing existence, and their negative counterparts, is found. Some only refer to pure existence (‘be’, ‘exist’), others aim at localizing the existence (‘be at’), either in a neutral way or, as shown by Lichtenberk (2002), by specifying the posture (‘be standing, sitting, lying’). Moreover, existential verbs are well known for expressing possession (Lyons 1967). This article aims to discuss the expressions of (non-)existence and localization in some New Caledonian and Polynesian languages, investigating how the languages express these notions and how they are interrelated: in specific compatibilities with tense-aspect and negative markers and in their choice of subjects (impersonal vs. personal, specific vs. nonspecific, animate vs inanimate). I will show that existential predicates and constructions manifest considerable diversity in Oceanic languages: in their lexical inventory, in their contrasts between affirmation and negation, in their semantic differentiations between ‘existence’ and ‘localization’ as well as in their constructional properties. Oceanic languages have more existential verbs than non-existential ones (Pawley 2000). The forms used for the various negative types (denial, negative verb, negative verbal marker, negative imperative), are identical or similar in some cases, but they can also be very different (Moyse-Faurie and Ozanne-Rivierre 1999).