Lichens are characterized as a symbiotic association, being composed of one or more fungi (mycobiont) and one or more green algae or cyanobacteria (photobiont). Lichens whose main photobiont is a cyanobacterium are called cyanolichens, and their photobiont is called cyanobiont. In this context, this study aimed to perform a literature review focusing on cyanolichens as biomonitors of environmental pollution and biomolecule production. The studies were found in different databases, by crossing the descriptors using the Boolean operators "OR" and "AND". Most cyanolichens belong to the division Ascomycota and species of the order Peltigerles. The most representative families in terms of species numbers were: Peltigeraceae, Lobariaceae, Collemataceae and Stereocaulaceae. Regarding symbiosis, most species are associated with Nostoc. Cyanolichens were considered as excellent bioindicators of natural and/or anthropogenic changes due to their high sensitivity to environmental pollutants, with Lobaria pulmonaria being the main species. They were also considered as organisms of high biotechnological potential due to the versatility of some species in synthesizing biologically active substances surch as: lecanoric acid, usnic acid, orsellinic acid, lobaric acid, evernic acid, atranorin, stictic acid, nostoclide I and lobarioid A, in biological activities (anticancer, antimicrobial, antioxidants, and antivirals). The study showed that cyanolichens are important not only for the performance of several functions, but also for their ecological role in ecosystems. There are still large gaps for the study of these organisms, so their development is pertinent to obtain current and complete knowledge.
