Pterygium pathogenesis has been mainly asso ciated with UV light exposure; however, this association remains quite controversial. The complete mechanism of pterygium also remains to be clarified. Factors such as inflammation, viral infection, oxidative stress, DNA methylation, inflammatory mediators, extracellular matrix modulators, apoptotic and oncogenic proteins, loss of heterozygosity, microsatellite instability, lymphangiogenesis, epithelial-mesenchymal cell transition, and alterations in cholesterol metabolism have been identified as causes. Several studies aimed to clarify the molecular mechanisms underlying the growth and proliferation of pterygium. Understanding its molecular basis provides new potential therapeutic targets for its prevention and treatment. A comprehensive search of the databases, namely, MedLine, EMBASE, and LILACS, was conducted with the following key words: pterygium, epidemiology, pathogenesis, biomarkers, and review. This review describes the epidemiology, clinical presentation, and current investigation of biological mediators involved in pterygium development.