The aim of this research was to determine length- weight relationship and condition of greater amberjack juveniles (Seriola dumerili) at the Mala Lamjana fish farm of the company Cromaris d.d. During September and October 2019 and March 2020, sampling and measurement of basic morphometric characteristics: total length (TL), weight (W), fork length (FL), body height and condition factor (CF) of greater amberjack juveniles (Seriola dumerili). The regression analysis was used to calculate the length-weight relationship of the fish as well as Fulton's condition factor. Negative allometric growth (b = 2.479; b = 2.221) was determined in September 2019 and March 2020, while positive allometric growth (b = 3.429) was recorded in October 2019. The condition factor in September was CF = 1.20 and in October CF = 1.21. In March the condition factor was slightly lower CF = 1.12. Performed measurements and analyses of the obtained results of this research indicate negative allometric growth of greater amberjack juveniles in breeding, meaning that individual fish improve more in length than they gain in weight. By comparing the results of this research with published papers, the condition factor in bred fish shows lower values compared to wild populations of greater amberjacks of the same category.