Aerobic bacterial flora in the intestines of seabream (Sparus aurata) larvae and juveniles, in diets they were fed (rotifers, brine shrimp, artificial diet), and in their rearing water were analyzed. Fish fed live feeds had a higher bacterial count than the fish fed the artificial diet. In rotifers, the total bacteria count was 8.7 x 10(6) and Pseudomonas dominated the flora (60.2%). In larvae fed rotifers, the bacteria count was 9.8 x 10(2), with Pseudomonas (48.4%) and Vibrio (28.3%) dominating. In brine shrimp, the bacterial count was 1.7-3.5 x 10(7) cfu/g and Vibrio (73.7-81.3%) was more prevalent than Pseudomonas (10.2-15.5%). In larvae fed brine shrimp, the bacterial count was 5.3 x 10(4)-1.8 x 10(5) and Vibrio (61.2-70.1 %) dominated. The count for the artificial feed was 1.2 x 10(4) with Pseudomonas slightly dominating while for juveniles fed artificial feed the count was 2.3 x 10(4), with Vibrio slightly dominating. Bacterial microflora in the rearing water ranged from 1.3 x 10(2) to 3.2 x 10(3) cfu/ml. The study showed that the microflora of fish feeds quantitatively and qualitatively affect the intestinal microflora of seabream larvae and juveniles.