The anaerobic treatment of leachate from a municipal waste transfer station in Malaysia was tested using a pilot scale anaerobic biofilm digester system that was operated under HRT sequence of 30-day, 25-day, 20-day and 10-day for 163 days under mesophilic conditions. Despite the leachate's complex characteristics, the system showed great performance given its maximum COD, BOD5 and total phosphorus removal efficiencies of 98 +/- 1%, 99 +/- 1% and 92 +/- 9% respectively. The system was stable throughout its operation and showed optimal average values for the monitored parameters such as pH (7.53 +/- 0.14), total VFA (79 +/- 66 mg HOAc/L), alkalinity (10,919 +/- 1556 mg CaCO3/L) and a non-toxic value for accumulated ammonia (960 +/- 106 mg NH3-N/L). Measurement of the average daily biogas production yielded a value of 25 +/- 1 m(3)/day throughout the system's operation with a composition of 57 +/- 12% methane and 26 +/- 6% carbon dioxide.