Abstract: A study was conducted to investigate the effects of dietary GroBiotic-A (1-3%) on growth and blood profiles of kutum (Rutilus frisii kutum) fingerlings (0.78±0.19 g) compared to fish fed an unsupplemented prebiotic in diet. After 8 weeks of feeding on the experimental diets, total protein, albumin, creatinine, compleman 3, compleman 4 and IgM were significantly higher (p = 0.05), in fish fed GroBiotic-A with 3% than control group. Other biochemical parameter such as glucose, aspartate aminotransferase, alanine aminotransferase, creatine phosphokinase, cholesterol, blood urea nitrogen, amylase, calcium, iron, phosphorus and magnesium were measured and compared to the control group (0% GroBiotic-A), dietary GroBiotic-A had no effect on serum. There were no significant differences in growth parameters between experimental groups and control group (p = 0.05). These results indicate that fish blood profiles could be affected by prebiotics which should be taken into account in preparing formula feed for artificial rearing fish.