The aim of this paper was to analyze the characteristics of the transactions between economic agents to identify their attributes and to determine their impacts on the governance structure of the forest biomass energy production chain in Lages, Santa Catarina state. The Economic Transaction Cost (ETC) was used as theoretical support. Fifteen entrepreneurs or company directors were interviewed to identify and characterize the transactions between the chain’s segments and to analyze the governance structure adopted by the agents. The companies involved in this study are located in twenty four municipal districts in the region. Analysis of the transactions between the agents demonstrated an increasing search for contracts, determined mainly by the need to guarantee the supply of raw material. This governance structure tends to be increasingly adopted by different segments of the production chain, especially in transactions involving residues, either for energy generation or other more noble uses.