This paper is an analysis of the relationship between the concepts of fisheries–science partnership (FSP) and fisheries co-management (FCM), using a case study of recent EU work on discard survival. Are FSP and FCM entirely different forms of joint activity, or is FSP a form of FCM or a means of preparing the ground for FCM? And is the recent EU work on discard survival a form of FSP, or of FCM, or both? A questionnaire was sent out by email in 2015 to 13 people who were involved in the discard survival work, and eight responses were received that covered eight projects in seven countries (Belgium, England, Denmark, France, Norway, Sweden, and the Netherlands). Our main findings are fourfold. First, while FSP and FCM are different forms of joint activity, they are both partnerships. Second, FSP may serve as a precursor or preparation for FCM. Third, the EU discard survival assessment work contains elements of both FSP and FCM, but is mainly a FSP exercise and falls far short of FCM. Nevertheless, fourth, this joint work alongside many other FSP initiatives undertaken under the auspices of the Common Fisheries Policy (CFP) (e.g., the GAP projects) has improved relations between fishers, scientists, and managers, and this may contribute to a modification of the CFP’s largely top-down decision-making system.