Abstract Koslow, J. A. 2009. The role of acoustics in ecosystem-based fishery management. – ICES Journal of Marine Science, 66: 966–973. For more than half a century, acoustics has been a leading tool in fishery stock assessment. Today, the need for ecosystem-based management poses new challenges for fishery scientists: the need to assess the ecological relationships of exploited species with predators and prey and to predict the potential effects of climate variability and climate change on recruitment. No research tool is likely to prove as effective as acoustics in meeting these needs, if it is properly integrated into interdisciplinary research programmes involving ecology and oceanography, as well as fisheries. Integration of data from acoustics and ocean-observation, as well as from satellites and other high-resolution oceanographic mapping tools, is likely to lead to major advances in fishery oceanography. New developments in acoustic technology, such as three-dimensional, multibeam acoustics, and shelf-scale acoustic mapping, may also lead to significant advances. Notwithstanding these developments, critical biases and shortcomings of acoustic methods that were noted 50 years ago remain with us. For example, the identification of insonified biota and single-target discrimination remains relatively primitive. Progress is urgently needed in these basic underpinnings of the acoustic method.