Economically sound decisions on fuel treatment require knowledge of treatment costs. Fuel treatment costs derived using an economic cost concept on two National Forests were found to be higher than reported by accounting methods. Costs are sufficiently high and variable to question the economic feasibility of fuel treatments. Regression analysis did not show a strong relationship between fuel treatment costs and the physical characteristics of treatment sites. Management behavior and organization constraints may more successfully explain the magnitude and variability of fuel treatment costs. There are economies of scale in larger fuel treatment projects. Fuels managers emphasized hazard reduction over silvicultural objectives but believe that hazard targets could be achieved with lower fuel treatment levels. West. J. Appl. For 1:116-121, Oct. 1986.