The aim of the presented research was to analyse the efficiency of forest management as an approach to promote sustainable multifunctional forestry. A total of 17 Regional Directorates of State Forests (RDSFs) in Poland were studied with the use of data envelopment analysis (DEA). This method has been proposed and tested using criteria and indicators (C&Is) as inputs and outputs of the created models. The research process was divided into two stages: first, we analysed the efficiency of simple DEA models and models with additional variables, which allowed us to determine the major models providing the best combination of efficiency evaluation criteria. Second, we used these models to assess the efficiency of sustainable management of forests by RDSFs. According to our results, RDSFs were found to be highly efficient in converting resources into production and nonmarket results. Nevertheless, the implementation of sustainable development principles requires further actions, in order to fulfil all ecological, economic, and social functions in a more effective way. They are connected with the necessity to increase the areas of both protective forests and promotional forest complexes. Thus, the results of this study might be a valuable source of information for the planning process of forestry services at the strategic and operational levels.