Pilot Plant Investigations have shown the feasibility of the Upflow Anaerobic Sludge Blanket (UASB) process in effectively removing about 90 percent of the COD contained in sugar industry effluents at an organic loading rate of 12.5 Kg COD/m3.day and a hydraulic retention time of 6 hours. Within the context of promoting the use of biotechnology for environmental protection, the Mauritius Research Council (MRC) funded the construction of a 50m3 demonstration plant at Rose Belle sugar factory, which was completed in September 1998. The main objective of this project was to determine the optimum criteria during the start-up phase of the treatment plant using a suitable inoculum and to operate it during two milling seasons. A proper equalization pond is a pre-requisite for the successful operation of any high-rate anaerobic system. Alkalinity has to be added to this pond to achieve a minimum concentration of 1500 mg/l CaCO3. The start-up of the plant has proved to be difficult and good quality sludge needs to be available. The presence of good quantity of seed sludge is the key for success of the UASB plant. It is proposed that in the Mauritian context the reactor be seeded either with septic tank sludge, anaerobic pond sediments or with imported granular sludge. Following the addition of a proper quantity of sludge in the reactor, the COD removal efficiency reached 70 percent during the 2001 milling season. The organic loading rate was 3.5 KgCOD/m3.day for a HRT of 24 hours. The organic loading rate can be further increased provided there is a good quantity of acclimatized sludge in the reactor. A pre-design cost estimation arrived at a capital investment of about Rs 12,000 per m3 of reactor. A 150 TCH factory will have to invest about 5 million rupees for a UASB treatment plant. The net annual operating cost is estimated at about Rs 3.00 per Kg of influent COD. Increased recycling of process water in industries will lead to lower amounts but higher concentrated effluents and an increased demand for anaerobic processed can be expected in the future. The effluent charges set by the Wastewater Management Authority (WMA) for discharge into sewers will increasingly lead to pre-treatment of industrial effluents using anaerobic technologies. The full potential of high-rate anaerobic technologies has so far not been exploited in the Mauritian context. There is a need for specialized training courses on anaerobic treatment for industry personnel and responsible authorities and financial organizations must be informed on the potential of these technologies.