Until this study an efficiency evaluation study had not been carried out down to the level of forest sub-districts in Turkey. In this research, it is aimed to evaluate the efficiency of the forest sub-districts in the Denizli Forestry Regional Directorate using fuzzy data envelopment analysis (Fuzzy DEA) for years 2007 and 2009. Fuzzy DEA solutions were carried out using the data range. Fuzzy data was established by defining the lower, central and upper limits on the basis of the triangular membership function. These data are converted into interval data considering the approach of Zimmermann (1991) α cutting set. Thus, the upper and lower limits of efficiency values were obtained at five different α (0; 0.25; 0.50; 0.75 and 1.00) using fuzzy data envelopment analysis. Then inefficient forest sub-districts were listed from best to worst using the Minimax Regret-Based Approach.