Olfactory imprinting is a specialized form of unconditioned learning in which olfactory information is acquired and used in specific behavioral contexts later in life. Olfactory imprinting behaviors were particularly evident in reproductive migration, homing, and spawning of some fishes, such as salmon. This brief review outlines the research progress on olfactory imprinting in fishes, including the physiological and molecular mechanisms, and its application in fishery conservation, with the goal of attracting attention to olfactory imprinting in fish habitat protection, stocking enhancement, and aquaculture, and providing guidelines for making decisions regarding fisheries conservation.