In the article, special attention is paid to practical realization of the "right to know" about pollutants using the World Wide Web. Five systems of PRTR (Pollutant Release and Transfer Registries) are introduced showing their typical features and variations. The varied PRTR information is provided by the UNEP organization. The access to Canadian system PRTR-NPRI (National Pollution Release Inventory) through Internet has been found to be the best way. Also British CHRI system (Chemical Release Inventory of the organization Friends of the Earth), American TRIS (Toxic Release Inventory System), Australian NPI (National Pollutant Inventory), and Czech ECONNECT are presented as very efficient tools for the practical realization of the "right to know".