The Chisasibi Child Language Acquisition Study (CCLAS) is a longitudinal naturalistic first language (L1) acquisition study of Northern East Cree speaking children located in the community of Chisasibi, Quebec (on the east coast of James Bay). The study focuses on production only. The children participating in the study were video-recorded at approximately two to three week intervals, with each filming session lasting, on average, 45 minutes. In most cases, filming covered a 30-month period (November 2004 to May 2007). There were six participants, three in a younger age cohort (around 2 years old in November 2004) and three in the older cohort (around 4 years old in November 2004). A total of 130 video-recordings were made. We wish to thank the CCLAS families in Chisasibi for their generous participation in this study – in a very real sense they have opened their homes to us, for no other reason than to play a role in supporting the vitality of their language. Principal funding for this project is provided by the Social Sciences and Humanities Research Council (SSHRC) of Canada (Standard Research Grant #410-2004-1836, Phonological and morphosyntactic development in a polysynthetic language: The acquisition of Cree as a first language), awarded to Brittain, Dyck, Rose and MacKenzie in 2004). Additional funding has been provided by the Cree School Board. The project web site is located at http://www.mun.ca/cclas.