This chapter is concerned with environmental crime and the enforcement of environmental law. It starts with some consideration of the difficult definition of ‘environmental crime’, including the distinction between moral and legal meanings of the term. Some of the basic framework of environmental crime, which helps to explain several of the approaches to the enforcement of environmental regulation, is then considered. For example, the fact that many environmental crimes are strict liability offences explains why the rate of successful prosecutions is high, but may also provide an explanation as to why some consider the sanctions that are imposed by the courts to be too low. A large part of the chapter is dedicated to a discussion of the enforcement practices adopted by regulatory agencies in England and Wales, including discussion of the use of civil sanctions instead of prosecutions and the recently enacted sentencing guidelines for environmental offences.