The investigations were made in a loop bioreactor, where biomass was immobilized in the ceramic carrier. The influence of the internal circulation rate on the biodegradation efficiency of brewery wastes by immobilized biomass and on production of surplus sludge was examined. The rates of the internal circulation were 12, 38, 50 dm3·h-1. The experiments were performed at constant loading rate of the carrier of 17.9 g·dm-3·d-1 and hydraulic retention time of 3 h. Increasing in the internal circulation rate from 12 to 50 dm3·h-1 caused enhancement of the removal rate from 0.40 to 0.48 gCOD·dm-3·h-1 and limitation of surplus sludge productivity from 0.67 to 0.27 g·g-1 COD removed. The biodegradation rate of brewery wastes in a two-stage immobilized system was determined. The hydraulic retention time in this two-stage immobilized system was 6 h, which was enough to get a COD below 150 mg·dm-3 in the effluent.