This book presents a documentation and analysis of Harsini, the language variety spoken by the people of Harsin, a small urban centre located in south-east Kermānshāh Province, western Iran. The main features of phonology and morphosyntax are outlined, and an extensive corpus of transcribed spoken texts, recorded in situ, is also provided, together with a lexicon. The book also includes comparative notes and discussion of the place of Harsini within Laki, and its relationship to Southern Kurdish. The sound files from the text corpus are available online at https://multicast.aspra.uni-bamberg.de/resources/kurdish/#laki