The pollack Pollachius pollachius is a commercially important fish, considered as a candidate for aquaculture in France. Rearing attempts are promising (Suquet et al., 1996), and more information is required about its reproduction, to contribute to a better management of breeders for this species. This study was designed to examine the first maturity in pollack and the effects of conditions such as origin and delayed reproduction season, on gonad maturation, reproductive and growth performances of adults.