The purpose of this article is to consider uncertainty in European Community law. It will be argued that, for reasons inherent in the nature of the Community, EC legislation is generally less clear and more difficult to interpret than British legislation. Five reasons are put forward as to why this might be so. While always undesirable, uncertainty is perhaps to some extent tolerable where Community legislation gives rights to the individual against public authorities: an uncertain right may, after all, be better than no right at all. It is, however, intolerable where obligations are imposed on the individual. One situation in which this arises is where directives are adopted in the field of private law, a rapidly increasing area of Community legislation. These measures will form the main focus of this study, though our attention will not be confined to them. Before considering these matters, we must, however, set the stage by making some preliminary distinctions.