The aim of this paper is to present a synoptic, schematic, but nonexhaustive review on insulin-like growth factors (IGFs) in fish. After recalling the common features between fish (essentially salmonids) and mammalian IGFs (essentially human), we underline some specific aspects of fish IGFs which concern their structure, their function, and their regulation. As important aspects of their physiology will be excluded (as, for example, information concerning IGF-BPs, the localization of IGFs, or the polymorphism of their cDNAs, etc.)