Thermomechanical pulping (TMP) is a highly energy intensive process where most of the energy is used in therefining of chips to fibres. Various ways of reducing the energy consumption have earlier been studied, for examplechange of refiner pattern, addition of various chemicals, and also some biochemical implementation in the form of fungus and enzymes. This study includes pre-trials with the enzymes pectin lyase and pectin esterase,multipectinase, xylanase, and mannanase. The results are studied via a reducing sugar assay, an enzymatic assayusing spectrophotometry, and capillary zone electrophoresis. The study also includes results from a pilot scalerefining with multipectinase, xylanase, and mannanase, performed with a wing refiner at Helsinki University.Reductions of energy consumption in TMP by pre-treatment of Norwegian spruce chips are investigated and apotential reduction of energy consumption of 6 % is indicated.