No ‘sustainable and efficient’ transport may exist without providing a system of liability of the transport operators which properly compensate damages for pollution generated by their activity. The case of oil pollution at sea is paradigmatic in order to understand the issues arising from the present regulation of this phenomenon and in particular the problems connected to the position of different kind of operators. In this perspective the Erika case has given rise to several decisions issued by the French criminal courts and the Court of Justice of the European Community. If the decision of the Court of Justice may be read as a fundamental statement on the coexistence between the international system of liability for oil pollution at sea and the European Directive on waste, the decisions of the French criminal courts have been a sort of ‘contradictory discussion’ over the fundamental principles of liability for oil pollution at sea, especially with regard to the ‘canalization’ of responsibility on the shipowner and its limits. The analysis of the decisions on the Erika case demonstrates that a fundamental question like ‘Who pays for oil pollution at sea?’ may receive unpredictable answers.