In this work, the efficiency of four microalgal species, namely, Chlorella vulgaris, Scenedesmus platydiscus, Scenedesmus quadricauda, and Selenastrum capricornutum to remove fluoranthene (1.0 mg l(-1)), pyrene (1.0 mg l(-1)), and a mixture of fluoranthene and pyrene (each at a concentration of 0.5 mg l(-1)) was evaluated. Results showed that removal was algal species specific and was also toxicant-dependent. Se. capricornutum was the most effective species while C. vulgaris was the least efficient species in removing and transforming polycyclic aromatic hydrocarbons (PAHs). PAHs removal in 7-days of treatment was 78% and 48%, respectively by these two. All species, except S. platydiscus exhibited higher fluoranthene removal efficiency than pyrene, indicating the latter PAH was generally more stable and recalcitrant. The removal efficiency of fluoranthene and pyrene in a mixture was comparable, or higher than the respective single compound, suggesting that the presence of one PAH stimulated the removal of the other PAH.