This paper presents the results of a pilot plant study using an Anaerobic Fluidized Bed Reactor (AFBR) for treatment of brewery wastes. A COD removal efficiency of greater than 75% was observed at an organic loading rate (OLR) of 9.5 kg COD/m3-day for a Deriod of 82 days from start-up. COD removal efficiency was greater than 74% at an OLR of 14.6 kg COD/m3 expanded bed (e.b)-day. A COD to methane conversion of 87% was achieved. Experimental results have suggested that the COD removal efficiency of an AFBR is only a function of COD loading, and neither the feed COD nor HRT alone significantly affect the performance of the reactor. A linear relationship was found between the specific substrate utilization rate and the specific methane production rate. It was observed that the distribution of the biomass along the height of the reactor is not uniform, and the biomass hold-up near the top of the reactor may reach concentrations of greater than 20,000 mg/l.