This is a first dictionary of the language called Bosavi, spoken by less than two thousand people who live on the Great Papuan Plateau north of Mount Bosavi, a collapsed volcano in the Southern Highlands region of Papua New Guinea. Bosavi is a Papuan (i.e.,non-Austronesian) language that is part of the Central and South New Guinea stock of the Trans-New Guinea Phylum. The variety of the Bosavi language represented in the dictionary is principally that spoken in the central Bosavi area where people identify themselves and their language as Kaluli. Kaluli is one of four mutually intelligible dialects spoken in Bosavi. This book's contents include a 20 page introduction to the Bosavi language, a 150 page Bosavi-English-Tok Pisin dictionary, a 20 page concise English-Bosavi dictionary and 8 appendices covering key areas of core vocabulary: family and relationship terms; body terms and counting system; the Bosavi longhouse; fish, reptiles, insects, animals and birds; forest, place and environment; food, food gathering and cooking; ways of speaking; sound words.