Across CEE, Oil & Gas Laws and Regulations are of utmost importance for both the legal sector and societies overall. Oil & Gas exploration and production have started over a century ago in countries like Poland and Romania, but the current dependence on a single source and the corresponding issues lead to the importance of the matter in the context of interconnectivity and security of supply. Over the last decades, my colleagues and I were devoted to providing legal assistance to the upstream, midstream, and downstream Oil & Gas sectors across CEE and we are delighted to share our knowledge within this CEELM Comparative Guide. The structure of the Guide is such that it provides the most important legal information structured in a practical way, which allows both focus on a single jurisdiction and cross-referencing and comparisons between the legal approaches in the various jurisdictions.