The zebrafish model organism database (ZFIN) provides a Web resource of zebrafish genomic, genetic, developmental, and phenotypic data. ZFIN curates and integrates data from current literature and from direct data submissions from laboratories. In addition, ZFIN collaborates with other bioinformatics organizations to provide links to other relevant data. These data can be accessed through a variety of Web-based search and display tools. This unit focuses on some of the basic methods to search, visualize, and analyze ZFIN data, including genes, gene expression, mutants, morphants, transgenics, anatomical structures, and antibodies. ZFIN's GBrowse genome viewer, BLAST, and protocol and antibody wikis are also discussed.