This paper presents the data management policy and procedures for Growing Up in Australia - the Longitudinal Study of Australian Children (LSAC), which will track the development of two cohorts of young children for at least seven years. It discusses key data management issues associated with the project, including: data management principles; file structure; data confidentialisation and access; data security; data imputation; outliers; weighting of data; respondent tracking; data linkage; and software implementation. For each of these issues, the paper outlines best practice to ensure the integrity of data management of the study.