Mango (Magnifera indica) seed kernel from Nigeria were analyzed for proximate composition, inorganic ions, amino acid composition, tannin and fatty acid composition. Mango seed kernel had 44.4% moisture content, 6.0% protein, 12.8% fat, 32.8% carbohydrate, 2.0% crude fiber, 2.0% ash and 0.39% tannin. Mango kernel fat contained high amounts of stearic (46.3%) and oleic (40.0%), while palmitic, linoleic, arachidonic and behenic acids were present in small quantities (<6.6%). Of the inorganic ions detected, potassium (365 mg/100 g), phosphorus (140 mg/100 g), magnesium (100 mg/100 g) and calcium (49 mg/100 g) were present in high levels, while iron, sodium, manganese and zinc were present in small levels (< 11.0 mg/100 g). The mango seed kernel is potentially a good source of nutrients for human and animal feed.