Digeston-1 (fermented soybean meal) is produced by controlled lactic acid fermentation with natural lactic acid bacteria. In the present study, a total of 150 fish with average initial body weight 10.11 g were randomly stocked into 15 aquaria to study the effect of Digeston-1 on performance and growth parameters of Nile tilapia (Oreochromis niloticus) fingerlings. Results revealed that the group fed diet contain Digeston-1 recorded the highest (P<0.05) growth parameters in terms of final body weight gain, average daily gain and specific growth rate compared with those fed the control diet. The Nile tilapia in the trial groups consumed less feed, which led to a considerable reduction of the feed costs. The results also showed that the FCR, PER and PPV% were high significantly (P<0.05) for fish fed diet containing Digeston-1 compared to fed control diet. Body composition; DM, CP, EE, Ash and energy content of Nile tilapia during the experiment showed no changes in whole body composition among all experimental diets. Results of Hematological parameters (WBCs, RBCs, Hb, PCV and Differential leucocytes count) of fish fed diets containing various levels of Digeston-1 indicated that there were no significant (P>0.05) differences among the tested dietary treatments. The treated diets had slightly higher white blood cells count, red blood cells count, hemoglobin and PCV than control diet. On contrast, total protein was increased (P>0.05) by Digeston-1 supplementation specifically, by 0.50% and 0.70% level. Moreover, Digeston-1 supplementation had no significant effect (P>0.05) on Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations compared with unsupplemented group. It is concluded that the addition of Digeston-1 diets at 0.5% level improve and enhance the growth performance of Nile tilapia, Oreochromis niloticus, fingerlings.