Abstract The aim of the present study is to assess the effects of selenium nanoparticles on the growth, hematology and nutrients digestibility of Labeorohita fingerlings. Fingerlings were fed with seven isocaloric sunflower meal-based diet supplemented with different concentrations of nanoparticles naming T1 to T7 (0, 0.5, 1, 1.5, 2, 2.5, and 3 mg/kg), with 5% wet body weight while chromic oxide was used as an indigestible marker. After experimentation for 90 days T3 treated group (1mg/kg -1Se-nano level) showed the best result in hematological parameters (WBC’s 7.97 ×103mm-3, RBC’s 2.98 ×106 mm-3 and Platelet count 67), nutrient digestibility (crude protein: 74%, ether extract: 76%, gross energy: 70%) and growth performance (weight gain 13.24 g, weight gain% 198, feed conversion ratio 1.5, survival rate 100%) as compared to the other treatment groups. Specific growth rates were found significantly higher in T5 than in other groups. The present study indicated positive effect of 1 mg/kg Se-nanoparticles on growth advancement, hematological parameters, and nutrients digestibility of L. rohita fingerlings.