It is a genetic, morphologic and chemical database of worldwide olive tree and oil having a double function. In fact, besides being a reference system generated for the identification of unkown olive or virgin olive oil cultivars based on their microsatellite allele size(s), it provides users additional morphological and chemical information for each identified cultivar. Currently, OGDD is designed to enable users to easily retrieve and visualize biologically important information (SSR markers, and olive tree and oil characteristics of about 200 cultivars worldwide) using a set of efficient query interfaces and analysis tools. Compared with other few existing databases for olive species, OGDD has its own specific features and advantages. In fact, it provides a reference system in evaluating the data obtained from the analysis of unknown samples and in defining the varietal composition of the virgin olive oil. It also contains a great deal of information for each cultivar identified by the user. This database can be used by all researchers and stakeholders interested in olive cultivar identification and virgin olive oil authentication.