Fingerlings of African catfish (Heterobranchus longifilis) were fed six isonitrogenous diets containing different levels of carbohydrates (15.30-40.55%) and lipids (7.01-20.32%), with carbohydrate: lipid ratios ranging 0.75-5.78, or a control diet (35% protein; carbohydrate: lipid 8.60) for 56 days. At the end of the trial, growth performance (body weight gain, specific growth rate) and feed efficiency (feed conversion ratio, protein efficiency ratio, protein gain, lipid gain) improved as the carbohydrate: lipid ratio increased from 0.75 to 5.29, however, beyond this point, they dropped. Likewise, protein and lipid body contents increased with the increasing carbohydrate: lipid ratio from 0.75 to 5.29, then fell. The carbohydrates had a protein sparing effect. The optimal dietary carbohydrate: lipid ratio for maximum growth performance of African catfish fingerlings was 5.29. This study shows that it is possible to incorporate local carbohydrate sources such as corn, millet, and sorghum in diets for African catfish, reducing the cost of feed production.