Mexico is responsible for the protection and management of a large number and variety of aquatic bodies of national and international importance. Environmental pollution by so-called persistent and bioaccumulative toxic substances (PBTS) poses significant risks for all of the world's aquatic ecosystems, especially in countries with emerging economies, where environmental regulations are often poorly implemented. In Mexico, the development of industrial projects and the deficient application of environmental regulations, together with the rapid increase in population and the inefficient disposal of urban waste, have generated a severe problem of water pollution in the country. National environmental protection programs have not included the monitoring of PBTS, even though researchers have been monitoring the main aquatic ecosystems of the country for nearly three decades, generating valuable information that could help improve the protection and exploitation of these ecosystems. The present work reviewed a large portion of the available literature (~150 articles) on aquatic biomonitoring of the main PBTS (Hg, Cd, Pb, POCs, and PCBs) in Mexico. This work aims to collect, synthesize, and facilitate the management and interpretation of the reported data to improve the country's aquatic ecosystems' protection and management.