The dictionary consolidates wordlists collected by Jacq and Sidwell during fieldwork to the Lao PDR (1996 to 1998), plus some material from other sources. The languages treated are Oi, Cheng, Sapuon, Talieng, Kraseng, Nhaheun, Laveh, Loven and Alak. The listing is according to semantic fields and includes both native vocabulary and borrowings, with some etymological commentary. The introduction includes a discussion of the current linguistic situation in the south of the Lao PDR, with maps and a listing of languages and villages where they are spoken. The recording and transcription of data is discussed, and some brief remarks are made on the phonology and grammar of the languages. A preliminary genetic classification based upon the lexical data is also presented. A bibliography of West Bahnaric studies completes the introduction.