Sea bass (Dicentrarchus labrax) inhabits coastal areas throughout Europe, belongs to the Moronidae family. It is farmed mainly in the Mediterranean area, mostly in Greece and Turkey, and in other countries such as Italy, Spain, Croatia etc. The most important factors that determine the growth and development of sea bass in cultivation are temperature and photoperiod. The catch weight of this type of fish ranges from 350 g to 3 kg. Males reach sexual maturity in the 2nd year of life, while females reach sexual maturity in the 3rd year of life. Sea bass spawning begins in November and lasts until March, and is an important biological process that ensures the preservation of the species. Spawning of farmed fish affects the costs of farming due to the energy consumption in the installation of gonads. In this thesis, the influence of sexual maturity on the condition index of farmed sea bass was evaluated during 12 months from several farms located in the middle Adriatic. Data of three age generations were collected, total mass, total body length, gonad mass and visceral mass were measured. The results of the research showed male dominance (90%) and higher average weight and length of females. Relationships were verified by linear regression. No statistically significant evidence was observed that would point to any significant association between the condition index and the gonadosomatic index. It is assumed that the main cause of the weak association is the high stability of the condition index through all three generations. The conclusions of this research points to the need for further research in order to better understand the factors influencing sexual maturity on the condition index of sea bass and their health in farming conditions.