Determining the distribution of the conservation burden and benefit is a critical challenge to the conservation and management of trans-boundary fish stocks. Given current levels of overfishing and overcapacity in many trans-boundary fisheries, some or all participating States must necessarily reach a compromise with regard to their interests and carry some share of the conservation burden. This article proposes a new approach to distributing the conservation burden and benefit in trans-boundary fisheries, and explores this approach in the world's largest tuna fishery: the tropical tuna fisheries of the western and central Pacific. Such an approach would enable Regional Fisheries Management Organizations (RFMOs) to transparently ensure that conservation burden and benefit distributions are consistent with international obligations. The article recommends that RFMOs consider developing decision-making frameworks that would enable existing scientific processes to determine the necessary extent of conservation measures, while a new conservation burden methodology would then determine the implementation of the measure and its impact on each member.