In this research, the biosorption of phenol using the fibres of a Mediterranean seagrass Posidania oceanica (L.) was studied. Batch experimental procedures were made to investigate the ability of this novel marine biomass to remove phenol from aqueous phase. The influences of pH and contact time at different initial concentrations were evaluated. The results showed that biosorption capacity was enhanced using solution pH equal to 5.2. The modelling results showed that pseudo-second-order and Redlich-Peterson models were found to be the most suitable to satisfactory describe the kinetic and equilibrium adsorption data, respectively.