A total no of 150 Nile tilapia fingerlings weight ranging from 4.06 g to 5.47 g were equally divided into 15 glass fiber tanks of 55L capacity. The total stocking weights were in the range of 48.63 g to 49.8 g. A probiotic (Promarine) was used at 0% (control, treatment 1), 0.5% (treatment 2), 1.0% (treatment 3), 1.5% (treatment 4) and 2.0% (treatment 5) inclusion rates in the experimental diets. The fish Nile tilapia were fed with 30% crude protein. The growth performance and nutrient utilization of Nile tilapia including weight gain, specific growth rate, and daily growth rate were significantly (P<0.05) higher in the treatment receiving probiotic than the control diet. The growth was significantly highest in treatment 2 (199.93 g) and treatment 4 (196.86 g). Similarly, treatment 3 (181.8 g) and treatment 5 (175.13 g) were significantly higher than the control diet (160.2 g). Similarly, the specific growth rate was also significantly highest in treatment 2 and treatment 4. The SGR was significantly higher in treatment 3 and treatment 5 than in the control diet. The feed conversion ratio in treatment 2 and treatment 4 was significantly lowest with other treatments but was non-significant with each other. The FCR was small in treatment 3 and treatment 5 than in the control diet. The feed with 0.5% and 1.5% Promarine probiotics inclusion showed significantly better performance in growth parameters as compared with other treatments.