This paper assesses the multiplexing efficiency of environmental taxes in ensuring environmental, energy, and economic security which is an integral part of sustainability in six European countries that are leaders in the Environmental Performance Index. This study aims to confirm the hypothesis that environmental taxes and payments could simultaneously affect changes in important environmental, energy, and economic security as well as sustainability parameters. Not all the previously selected taxes, which affect the parameters of all three areas of environmental, energy, and economic sustainability and security can ensure their simultaneous growth. Calculations made for the period 1994-2019 showed that in the system of environmental taxation of Denmark, five environmental taxes and fees provide an increase in the integrated level of environmental, economic, and energy security and sustainability; in Belgium, two environmental taxes are characterized by multiplex efficiency; in France, seven environmental taxes and payments; in Austria, four; in Finland, one; and in the UK, four. The paper's findings could create the basis for improving environmental taxation systems in the countries to increase comprehensive national security growth and ensure sustainable development path of the countries.