Mian is a non-Austronesian ('Papuan') language of the Ok family spoken in the Highlands fringe in western Papua New Guinea. Mian has approximately 1,400 speakers and is highly endangered. This grammar is the first comprehensive description of the language. It is based on primary field data consisting of a text corpus that covers different genres of the oral tradition, namely myths and ancestor stories, historical accounts, accounts of the initiation ritual, conversations, and procedural texts. The corpus was recorded by the author during a total of eleven months of field work from 2004 to 2008. The book provides a thorough description of all areas of Mian grammar and gives an in-depth analysis of many points of typological interest, such as the complex system of lexical tone, the interaction between a gender system and a system of classificatory prefixes on verbs of object movement, manipulation or handling, which allows the highlighting of certain characteristics of a referent in a given situation, the complex verbal morphology which allows fine-grained tense-aspect-mood distinctions, and a switch-reference system in which switch-reference suffixes on medial verbs are homophonous with and derived from suffixes functioning as tense and aspect markers in final verbs. The book is rounded off by a collection of traditional and contemporary texts (fully glossed and translated) and a word list comprising some 1,600 items, giving lexical tone, word class and meaning.