Present trial was conducted to evaluate effects of probiotics on mineral absorption, haematology and carcass composition of Oreochromis niloticus fingerlings fed canola meal-based diet. Six test diets were prepared by using graded levels of probiotics (Protexin) such as 0, 1, 2, 3, 4 and 5 gKg-1 level in the canola meal based diet. Triplicate tanks were used for each treatment and 15 fingerlings were stocked in each replicate. Fingerlings were fed at the rate of 5 % of live wet weight. Plant meal based diets in the absence of probiotics played negative effect on fish growth performance. Chromic oxide (1%) was added in the diets as inert marker. It was noted that probiotics supplementation played a significant role in improving absorption of minerals, carcass composition and haematology of fish. Higher mineral digestibility (Ca 76%, Fe 62%, Zn 57%, P 76%) and carcass composition (crude protein 17% and crude fat 10%) was found in fish fed on 3 gKg-1 level of probiotics supplemented canola meal based diet. Whereas higher ADC% of Na (75%), K (67%) and Mg (62%) were recorded by fish fed on 4 gKg-1 level of probiotics supplemented canola meal based diet. Similarly maximum improvements in RBCs, WBCs and Hb as well as higher mineral absorptions were recorded in fish fed on the said test diet. On the basis of these results it was concluded that probiotics supplementation at 3 gKg-1 level in canola meal based diet is helpful for maximum performance of Oreochromis niloticus fingerlings.