The Autism Chromosome Rearrangement Database (ACRD) is a comprehensive database of structural variation related to autism extracted from publicly available literature as well as unpublished data. The database is available at: http://projects.tcag.ca/autism/ and is hosted by the Centre for Applied Genomics at Hospital for Sick Children. The ACRD facilitates the interpretation of autism spectrum disorders (ASDs) structural variation data in relation to previously published work, providing a valuable resource for both clinicians and researchers. The database is continuously updated with in-house experimental data and data from published research studies. As of July 2009, the content of the ACRD was based on results from 279 peer reviewed journal articles as well as unpublished data. These structural variation entries are composed of 171 apparently balanced changes and 323 large cytogenetically detectable unbalanced changes. The data are represented in table format and in a genome browser format where molecular breakpoints are defined. The genome browser is based on the widely used generic model organism database (GMOD) software called GBrowse and is ideal for viewing structural variation in the genome such as genes and segmental duplications. The development team also accommodates the submission of data and comments regarding the database from the research community. Both cytogenetic and microarray data can be accessed using the database. The database was first described in Xu, J., Zwaigenbaum, L., Szatmari, P. and Scherer, S.W. 2004. Molecular Cytogenetics of Autism. Current Genomics 5(4), 347-364. The development of the database is supported by The Centre for Applied Genomics at the Hospital for Sick Children as well as the McLaughlin Centre for Molecular Medicine.