This chapter examines the concept of liability and its role in the environmental context. The analysis will focus on the application of liability as a response to environmental damage and will seek to demonstrate how traditional concepts of liability have progressively evolved and adjusted to accommodate a more specific environmental dimension. In that perspective, the chapter will begin with a brief theoretical background into the main features and rationales of liability both as a traditional legal concept and as a tool of environmental law and policy (section 2). It will then trace the historical evolution of liability rules face to the advent of modern industrial technologies, the intensification of risks and the specific problems posed by environmental pollution (section 3). In this respect, the transnational dimension of the damage and the role of international law will be discussed. Section 4 will discuss emerging trends in the law of liability with respect to damage to the environment and natural resources. While the chapter will primarily focus on international law developments, it will also discuss significant developments which have taken place at the regional and domestic level to the extent that they had a meaningful influence on the definition of the international legal framework and contributed interesting insights into prospective application of liability rules to fulfil the goal of environmental protection.