The current research work is focussed on optimizing dietary pantothenic acid requirement of fingerling catla, Catla catla. Triplicate groups of fish (3.3 ± 0.37 g) were fed with seven isonitrogenous (350 g/kg CP) and isoenergetic (16.72 kJ/g GE) purified diets containing 0, 10, 20, 30, 40, 50 and 60 mg pantothenic acid per kg thrice daily for 16 weeks. Absolute weight gain (AWG), specific growth rate (SGR), protein efficiency ratio (PER) and protein gain (PG) increased significantly as dietary pantothenic acid levels increased from 0 to 30 mg/kg, whereas the feed conversion ratio decreased. Fish fed diets supplemented with 30 mg pantothenic acid per kg diet had highest hematocrit (Hct), RBCs and hemoglobin (Hb) concentration. Thiobarbituric acid reactive substances values were found to be highest in fish fed basal diet which decreased with the increase of pantothenic acid up to 30 mg/kg whereas, liver superoxide dismutase and catalase activities increased with increasing concentration of dietary pantothenic acid up to 30 mg/kg diet. However, Intestinal protease, amylase and lipase activities significantly (P < 0.05) increased as the amounts of dietary pantothenic acid increased up to 30 mg/kg and then leveled off. Fish fed 30 mg/kg pantothenic acid reflected significantly higher (P < 0.05) lysozyme, tissue serum protein and alkaline phosphatase activities than fish fed the pantothenic acid-deficient diets. Liver pantothenic acid concentration was highest in fish fed diets with 40 mg pantothenic acid per kg diet, followed by 50 and 60 mg pantothenic acid per kg diet. Broken-line regression analysis of AWG, PG, lysozyme and liver pantothenic acid concentrations versus varying levels of dietary pantothenic acid exhibited the pantothenic acid requirement in the range of 28.70–38.46 mg/kg diet.