The Swedish woodfuel market has grown rapidly in the past ten years. Government policy has strongly supported this development and environmental taxes on fossil fuels have been introduced. This has favoured untaxed biofuels, i.e. woodfuels, in the district heating sector where the market has grown very rapidly. This study on price formation is based on the earlier knowledge of the market and shows that the woodfuel market has seen a dramatic increase combined with falling prices. Unrefined wood fuels demonstrate an annual volume increase of 13% while real prices have fallen at an annual rate of 5% during the first half of the 1990s. Total taxes paid by the district heating sector have increased during the period studied and of which taxes for fossil fuels have increased dramatically during the past ten years. However, tax as a share of the total fuelmix supplying the district heating sector has been stabilised over time. The primary reason for this development is the replacement of the highly taxed fossil fuels in the supplied fuels with untaxed, biofuels. Companies have reacted very quickly and rationally from an economic point of view to the rising costs of fossil fuels, substituting an increasing share with biofuels. For the future, many utilities have the capacity to adapt to new changes in costs resulting from either changes in fuel prices, changes in fuel taxes or changes in prices on heating or electricity markets.