Fish gametes convey not only genetic but also epigenetic information to the offspring. In this chapter, we review the current knowledge on the establishment of the epigenetic profile in the germline during gametogenesis in fish, from the primordial germ cells to the terminally differentiated spermatozoa and ova. The role of the gamete epigenetic profile in the transmission of epigenetic information to the offspring is described, together with the question of parental imprinting, or lack of it, in fish. The second part of this chapter focuses on the sensitivity of the fish gametes epigenome to the effects of some specific environmental factors, namely environmental contaminants, domestication, and reproductive biotechnologies. Whether or not these changes are transmitted to the next generation is also discussed.