Various indices related to reproduction and the fecundity of Helicolenus dactylopterus dactylopterus (Teleostei: Scorpaenidae) were analysed. Sexual dimorphism does not occur in the population we studied and the sex ratio is always equal. The size of the species at sexual maturity is a standard length of 130 mm for males and 145 mm for females. The maximum gonadosomatic index values for males and females are temporally out of phase to a large degree, which explains the intra-ovarian storage of spermatozoa that occurs in this species. There are large hepatic reserves which are basically used in the synthesis of vitellogenin, while the mesentery fat reserves are not mobilized until the end of the maturation process of the oocytes. Multiple spawning takes place between January and February, consisting of between 11,000 and 87,000 eggs, of about 500 μm in diameter. The fecundity of the species is, with a high degree of correlation, determined by the size and weight of the individuals.