This book is based on a research studied the adoption and discontinuance of adopted improved fisheries technologies in southwest Nigeria using a multi-stage sampling technique. Major constraints to adoption included cost, credit, labour intensiveness, in-sufficient awareness, withdrawal of subsidies, extension contact, farmers? perceptions and technologies? characteristics. Innovations disseminated to the farmers must therefore be economically affordable, simple, appropriate, institutionally supported, invented through participatory approach and compatible with fisheries practices. Farmers joining associations and establishment of farmer field school are recommended to enhance adoption. It focuses on sustaining the gains of technology derivation, dissemination and adoption among farmers. It investigated the role of fisheries extension in the adoption and suggested ways by which it can be well adapted to perform effective advisory service. It highlighted the constraints to adoption and discontinuance of improved fisheries technologies. The beneficiaries were the fish farmers, artisanal fisher folks, fish handlers, the policy makers, extension agents, researchers, donor agencies.