The nutritional value of Jack bean (Canavalia ensiformis) in animal feeds have been limited by the presence of antinutritional factors. This study investigates the efficacy of toasting as a processing method in improving the nutritional value and the utilization of C. ensiformis seeds in the diet of Clarias gariepinus. Result obtained reveals that the proximate composition of toasted C. ensiformis seed was not significant affected when compared to the raw seed. However, many essential amino acids were significantly reduced by toasting. Of all phytonutrient isolated in the seed, lectin and canavaline were not markedly reduced with toasting. Fingerlings of C. gariepinus fed diets (35%CP) formulate by substituting soybeans (inclusion at 38.19%) with C. ensiformis at 0, 5, 10, 15 and 20% revealed significant reduction in growth as the substitution levels increased. It was concluded that toasting alone is not an effective method for improving utilization of C. ensiformis in the diet of African catfish. Research on other processing methods or are recommended