The goal of the present research was to study the ability of Corynebacterium glutamicum MTCC 2745 immobilized on Sawdust/MnFe 2 O 4 composite to treat arsenic bearing wastewater by simultaneous biosorption and bioaccumulation (SBB) system at laboratory scale and also to investigate the influences of initial pH, biosorbent dose, contact time, temperature and initial arsenic concentration on biosorption/bioaccumulation of both As(III) and As(V). The surface texture of the immobilized bacterial cells was investigated through SEM-EDX analysis. The presence of functional groups on the surface of immobilized bacterial cells that may interact with the metal ion was confirmed by FT-IR. The pattern of biosorption/bioaccumulation fitted well with Vieth and Sladek isotherm model for As(III) and Brouers-Sotolongo and Fritz-Schlunder-V isotherm models for As(V). The maximum adsorption capacity estimated using Langmuir model was 1672.32214 mg/g for As(III) and 1861.71453 mg/g for As(V) at 30°C temperature and 240 min contact time. The results showed that As(III) and As(V) removal was strongly pH-dependent with an optimum pH value of 7.0. The effect of co-existing ions, such as Cu 2+ , Zn 2+ , Bi 3+ , Cd 2+ , Fe 3+ , Pb 2+ , Co 2+ , Ni 2+ , Cr 6+ and SO 4 2− , at different concentrations were examined. Desorption study exhibited that over 81.34 and 88.727 % could be desorbed from immobilized bacterial cells with 0.05 M NaOH solution.