This article deals with the phonetic-phonological status of the interdental consonants (Formula presented), in the Mapudungun spoken in the Coastal area of the Huapi Island, IX Region of Araucania. After analyzing minimal pairs, quantification of interdental segments versus alveolar (Formula presented), and the phonological awareness of the assessed speakers, the validity of these segments could be concluded both as phones and as phonemes. That is to say, (Formula presented), are phonemes in this area.