Rotokas is a language spoken in central Bougainville Island, Papua New Guinea, and is known for having one of the smallest phoneme inventories in the world. The language features a remarkably simple phoneme system, consisting of only 12 phonemes: six consonants (p, t, k, b, d, g) and five vowels (i, e, a, o, u). This minimal phoneme count places Rotokas alongside Pirahã as one of the languages with the fewest phonemes globally. The simplicity of its phoneme system makes Rotokas a fascinating subject for linguistic research, demonstrating the flexibility of human language capabilities. Despite its linguistic significance, Rotokas is endangered, with approximately 4,320 speakers recorded in 1981, though the current number of speakers is unknown. Preserving linguistic diversity is crucial for maintaining cultural heritage, and Rotokas stands as a testament to the adaptability of human communication. The language belongs to the East Papuan language family, specifically the Bougainville subgroup, and is closely related to Kunua and Keriaka languages. The geographical location of Bougainville Island has likely influenced the development and characteristics of Rotokas, which has evolved its unique phoneme system over time. Further research is needed to fully understand the historical development and relationships of Rotokas with other languages.