This research was conducted to evaluate the effects of Se and Cr nanoparticles supplemented sunflower meal based diet on growth performance, carcass composition and nutrient digestibility of Indian Major Carps (Catla catla, Labeo rohita and Cirrhinus mrigala) fingerlings. Nano Se and Cr were added in sunflower meal based diet having graded levels (0, 0.5, 1, 1.5, 2, 2.5 and 3 mg/kg). Chromic oxide was added as indigestible marker at the rate of 1% to estimate the nutrient digestibility. 15 fingerlings were stocked in V-shaped tanks and fed at the rate of 5% of their live wet weight. Feces from each tank were collected twice a day to estimate the nutrient digestibility. Effects of each treatment on the weight gain%, feed conversion ratio (FCR), carcass composition, hematology, minerals absorption and nutrient digestibility were calculated by standard methods and formulae. Maximum growth performance (208% WG, 1.4 FCR, 1.25 SGR and 100% survival), nutrient digestibility (CP 76%, EE 79% and GE 75%), carcass composition (protein 63 and fat 15), hematology (RBCs 3.16 ×106mm-3, WBCs 8.06 ×103mm-3 and Hb 9 g/100ml) and mineral absorption (Ca 73%, Na 75%, K 74%, Cu 68%, P 76%, Zn 62% and Al 62%) was noted in C. catla fingerlings fed at 1.5 mg/kg supplementation levels of Se-nano particles and 2 mg/kg supplementation levels of Crnano particles, respectively. While in case of L. rohita and C. mrigala fingerlings almost all above said factors were best at 1 mg/kg supplementation levels of Se-nano particles and 1.5 mg/kg supplementation levels of Cr-nano particles, respectively. Water quality parameters in each tank were monitored on daily basis throughout the experiment (90 days).