Businesses' efforts to increase efficiency and optimize business activities lead them to various strategic decisions. One of them is outsourcing, that is, the transfer of certain activities to external entities that perform them with lower costs and higher quality. However, in contractual relationship transaction costs are occurring and may ultimately outweigh the cost savings of outsourcing. This also applies to forestry, where most of silvicultural and harvesting activities are carried out by hired contractors. The aim of the thesis is to evaluate the transaction costs associated with outsourcing of forestry services in selected forestry enterprises. The theoretical part explains the concepts of outsourcing and transaction costs. Methodically, the thesis is based on case studies that are developed through a structured interview with users of forestry services. Consequently, it is possible to draw conclusion on the functioning of the forest services market from the transaction costs perspective and make recommendations.