Performance of anaerobic upflow fixed film reactors for biomethanation of high-strength cheese whey using different support material such as charcoal, gravel, brick pieces, PVC pieces and pumice stones at 37 degrees C has been studied. Among them the charcoal fixed film reactor showed the best performance when operated at 2 d hydraulic retention times (HRT), achieving maximum COD removal of 81% (COD influent=70 g/l) and improved total gas production (6.7 l/d/l digester) with high methane content (72%).