Abstract Regulation 178/2002 contains a definition of the precautionary principle. This is the first time a legal definition of the principle has been formulated for all EU food law. This fact, however, has been given hardly any attention in literature. It is all the more surprising because the lack of clear formulation of this concept was the main reason for criticism and controversy surrounding the principle. In the absence of a definition, the precautionary principle was a general notion, similar to the principles of subsidiarity or proportionality. Its scope was determined by decision makers and ultimately shaped by tendencies in case law. After codification, existing policy orientations and earlier case law may in some aspects differ from the legal definition. This article characterizes the main constituents of the precautionary principle and the risk analysis methodology established in Regulation 178/2002 and discusses examples illustrating how different provisions of the Regulation narrow the scope of the principle. It focuses on issues critical to its application: emergency measures, the so-called other legitimate factors, the burden of proof, and pre-market approval schemes.