The intensive production of polycyclic aromatic hydrocarbons by anthropogenic activities is a serious environmental problem. Therefore, new bioremediation methods are required to avoid widespread contamination. In this work, Serratia sp. AC-11 strain isolated from a tropical peat was selected for immobilization into chitosan beads, which were employed in the biodegradation of fluoranthene. The sizes of the produced beads were relatively uniform with an average diameter of 3mm. The material was characterized by SEM and FT-IR, confirming the cells immobilization and the protective barrier formed by the chitosan surrounding the biomass. The immobilized bacteria were able to degrade 56% of fluoranthene (the initial concentration was 100mgL(-1)) in just 1day at twice the degradation rate achieved by free-living cells. Furthermore, the immobilized bacteria showed excellent removal during five reuse cycles, from 76% to 59% ofbiodegradation. These results showed the potential of this approach for remediation of contaminated sites.