The objective of this study was to determine the effects of the prebiotics Immunoster and Immunowall (two commercial prebiotics) on growth performance of juvenile beluga (Huso huso). Prior to the feeding trials, fish were fed the basal diet to apparent satiation four times per day for a 4-week acclimatization period. The basal diet contained 42% crude protein, 14.5% crude lipid, 10.06% ash and 6.1% moisture. Then, 450 beluga juveniles weighing 95.6 ± 9.4 g were randomly distributed into 15 fiberglass tanks (2 · 2 · 0.53 m) in three replicates and kept at a density of 30 fish per tank. Two levels (1 and 3%) of Immunoster and two levels (1 and 3%) of Immunowall were added to the basal diet in place of cellulose.