The purpose of this paper is to identify the role of the polluter pays principle (hereafter PPP) and other connected key legal principles, as the pre-cautionary principle (art. 191 TFEU) in energy taxes in a State aid context. This analysis will be performed in accordance with the European Commis-sion regulations and decisions in the field, and some relevant European Court of Justice cases. For this purpose, section 1 defines the proper scheme of the analysis that can be inferred from those sources. Section 2 fixes the set of prin-ciples to be taken into account for this objective. Section 3 identifies some specific rules useful in the field to inform the legal policy of Member States in order to design energy taxes respectful with European Law on State aid. Sec-tion 4 highlights the importance of taking alternative approaches into consid-eration. Finally, section 5 presents a set of conclusions.