Data on 537 Arboviruses and 180 other viruses have been collected and coded in two different formats. These data include information not only regarding the taxonomy and history of isolation, but also regarding the properties of biomacromolecules, proteins and nucleic acids. Information on antigenic relationships, histopathology and experimental viremia is also included. This information is stored in formats which allow the manipulation and analysis of data by dBASE III PLUS and MICRO-IS. A set of programs was written for interconversion and editing purposes. Transmission electron micrographs are scanned and stored. This stored information can be used in viral classification as shown by carrying out analysis of data on the Bunyaviridae family.