Polycyclic aromatic hydrocarbons (PAHs) are common contaminants of terrestrial and aquatic ecosystems. Traditional, toxicological studies for defining the potential hazard of PAHs in wildlife have been conducted in the absence of UV radiation. However, recent toxicology studies particularly in the discipline of aquatic toxicology have presented evidence that PAHs may become toxic or substantially more toxic upon coexposure to UV light (300-400 nm). In this paper, a comprehensive review of the literature pertaining to the toxicological interaction of PAHs and UV light in aquatic and terrestrial organisms is presented. It is concluded that the acute phototoxic effects of PAHs should be considered when conducting environmental risk assessments; however, more research needs to be conducted to address the lack of data on the enhancement of UV-induced carcinogenesis by PAH compounds.