Study of growth performance of fingerlings of Clarias gariepinus (Burchell, 1822) fed Sesamun indicum (beni seed) as a supplementary diet was carried out for 8 weeks. 195 samples were used for this study. Diet A was commercial feed that served as control. Isoproteic diets (40% crude protein) were formulated at 25%, 50%, 75% and 100% inclusion of beni seed and designated as diets B, C, D and E. Final weight and body weight gain were recorded highest in diet A (control), which differ significant differences (p0.05) from other beniseed diets. Feed intake differ significantly between diet D (75%) and other diets except diet C (50%). Feed efficiency ratio revealed that diet A (control) was best utilized although diet C (50%) which is better did not differ significantly (p>0.05) with other diets. Specific growth rate (SGR) did not show any significant difference between control and formulated diets. Feed conversion ratio differ significantly (p0.05) between diet A and other diets. S. indicum can be utilized at a very high level of inclusion in the feed of Clarias gariepinus fingerlings. S. indicum should be used as an ingredient in the diet of C. gariepinus fingerlings, high level of inclusion (100%) is recommended for use in fish diet, other culturable species of fish like Tilapia and Carp should be used for similar work and this study should be used as a guide for other similar research work.