Abstract: Energy security and carbon dioxide emissions reduction are two key objectives of the governments’ energy policy. This article analyzed some of the policy instruments which may affect both objectives and made clear the impact they have on each one. The study shows that instruments benefitting both objectives are those aiming at enhancing energy efficiency, developing non-fossil energy and promoting the new technology. Some measures used to adjust the structure of energy-mix may have contrary effect on the two objectives and should be implemented with caution.