Due to the involvement of scientific, industrial, commercial and public sectors of society, the complexity of the issues concerning the safety of genetically modified organisms (GMOs) for the environment, agriculture, and human and animal health calls for a wide coverage of information. Accordingly, development of the field of biotechnology, along with concerns related to the fate of released GMOs, has led to a rapid development of tools for disseminating such information. As a result, there is a growing number of databases aimed at collecting and storing information related to GMOs. Most of the sites deal with information on environmental releases, field trials, transgenes and related sequences, regulations and legislation, risk assessment documents, and literature. Databases are mainly established and managed by scientific, national or international authorities, and are addressed towards scientists, government officials, policy makers, consumers, farmers, environmental groups and civil society representatives. This complexity can lead to an overlapping of information. The purpose of the present review is to analyse the relevant databases currently available on the web, providing comments on their vastly different information and on the structure of the sites pertaining to different users. A preliminary overview on the development of these sites during the last decade, at both the national and international level, is also provided.