The growing demand for electricity in large Brazilian cities and the distance to the region with the largest energy production have encouraged the construction of transmission lines thousands of kilometers long, crossing several states of the federation. Therefore, the heterogeneity of requirements in federal, state and district environmental laws tend to lead to uncertainty for the investor regarding procedures and investments necessary for the completion of the project, as well as the time that the requirements will take to be fulfilled. In the present study, we identify and compare the criteria used by the various environmental licensing agencies for classifying transmission system projects in the different procedures (simplified and ordinary) of environmental licensing. It was possible to expose the differences and demonstrate some inconsistencies in the legislation of some Brazilian states. In particular, we note an absence of proportionality between the licensing requirements and the expected environmental impacts for projects on the physical, biological and social environments. Additionally, it was identified subjectivity in the requirement for social participation through public hearings, demanded by the legislation for the projects classified in the ordinary procedure.