Epi Info is a general-purpose set of computer programs for word processing, database management, statistics, and graphics developed over the past five years at the Centers for Disease Control and the World Health Organization. The programs allow rapid questionnaire construction, data entry, and analysis during epidemic investigation. Both data entry and analysis can be programmed to provide customization and automatic operation for more permanent systems, such as those for disease or injury surveillance. Epi Info is in the public domain and copies may be freely distributed. It requires an IBM-compatible micro-computer with at least 512 kilobytes of memory. Translations into French and Spanish are in progress; a translation kit is available to facilitate translation into other languages.