Rapid industrialization for sustaining economic stability is leading to the pollution of environment due to disposal of untreated wastewater. Distillery is one of them which is agro based Industry generating huge quantity of wastewater or spent wash and it poses problems of disposal to acceptable standard due to its high BOD, COD, Color, Odor etc. Aerobic treatment alone is not feasible due to its energy intensive operation. So in this context anaerobic treatment of high BOD distillery wastewater seems to be an appropriate option of primary treatment, in the end of pipe treatment of distillery wastewater. This paper discusses about the operation and the result of Pilot Plant Studies on Upflow Anaerobic Fixed Bed Reactor in Biphasic Reactor System for Treatment of distillery spent wash. The Continuous Stirrer Tank Reactor (CSTR) was first phase and it serially connected to Upflow Anaerobic Fixed Film Reactor (UAFFR). This biphasic reactor system was operated for period of six months and several process parameters were monitored during this operational period. The UAFFR Reactor was started up with maximum Hydraulic Retention Time (HRT) of 99 days and minimum Organic Loading Rate (OLR) of 1.11 kg COD/M3/d and COD reduction was 65%. After 6 months treatment of spent wash in biphasic reactors it was found maximum OLR 5.38 kg COD/M3/d at HRT(Hydraulic retention time) of 18 days and given around 68% COD reduction in a stabilized phase. This study shows that there is further scope for increasing OLR and decreasing the HRT of the reactor. © Global Science Publications.