This article reviews methods used in the increasing use of fishers' knowledge in contemporary fisheries management. During the last one hundred years, fisheries science has been used extensively to inform management decisions for the regulation of sea fisheries. However, the decline of many fish stocks has cast doubt on the sufficiency of fisheries science, and has led to demands from fishers that their own expertise—fishers' knowledge—should be taken into account in decision-making. In this article, we examine four case studies of such attempts to take account of fishers' knowledge in the management of North Sea fisheries, comparing their different methods of identifying and using fishers' expertise, and assessing their respective outcomes. Our conclusion is that the value of fishers' knowledge improves according to the extent to which the method of obtaining it is participative and interactive.