Abstract: Contamination of polycyclic aromatic hydrocarbons (PAHs) in the environment is a serious health problem and new technology employing organisms especially microorganisms to remove PAHs from contaminated environments has been proposed. However, information related to the role of algae in bioconcentration and metabolism of PAHs are widely scattered in spite that hydrophobic chemicals may enter the food-chain by bioconcentration from water into the algae, and algae are capable of accumulating and metabolizing PAHs after their bioconcentration. This review presents the current knowledge about bioconcentration of PAHs by algae and metabolic pathways and enzymes involved in PAHs metabolism. The bioconcentration are detailed in compounds-dependent, species-dependent as well as biomass-dependent. The bioconcentration of PAHs by live and dead cells were also compared. In addition to the bioconcentration, the metabolic pathways of PAHs by fungi, bacteria and algae are included. Finally, the enzymes involved in metabolic process for organic chemicals in plants are presented.