Bycatch in pelagic longline fisheries is one of the greatest threats to seabirds, particularly albatrosses and petrels. The Agreement on the Conservation of Albatrosses and Petrels (ACAP https://acap.aq/) provides a range of advice, guidelines and resources aimed at advancing the conservation of albatrosses and petrels. ACAP routinely reviews and updates its advice, most recently in May 2019, at the Ninth Meeting of the ACAP Seabird Bycatch Working Group and the Eleventh Meeting of its Advisory Committee, and this paper outlines the latest advice and resources available. ACAP Parties noted with concern the continuing conservation crisis facing albatrosses and petrels, and the need for urgent and increased efforts to counter this crisis. Despite all the research and attention devoted to the development of best practice bycatch mitigation measures, these have not been sufficiently implemented to halt the decline of many albatross and petrel populations. This included lack of compliance with measures required by regulatory bodies. Within jurisdictions where enforcement had occurred, reductions in seabird bycatch were demonstrated, sometimes dramatically so and without perceived detrimental consequences arising. ACAP is in the process of developing new and augmented areas of focus and activities for the immediate and longer term, including an ongoing emphasis on ways in which it can work with Regional Fisheries Management Organizations and others to enhance implementation of strategies and actions to reduce bycatch of seabirds in fishing operations, acknowledging that this needs to be done at a range of different scales. In addition, ACAP is working towards communicating more effectively the conservation crisis facing albatrosses and petrels, and its advice regarding how best to address the threats that these seabirds face.