Fruits constitute an important part of a balanced diet as they are natural sources of food nutrients. Most of the harvested produce ordinarily is left lying on the farm and at home. These plant nutrients degraded shortly after harvesting as a result of biochemical changes. The effect of storage after harvesting on African star apple fruit at ambient temperature (28±2°C) was investigated on alternate days (1, 3 and 5). Its pulp, peel and seed were investigated in terms of their proximate composition, vitamin C, mineral elements and antinutrients using standard analytical techniques. The results showed a significant (p˂0.05) difference in the percentage proximate composition of African star apple fruit pulp and peel while there was no significant (p˃0.05) difference in moisture and crude protein of the seed at the storage days 1, 3 and 5. Greater percentage increase of moisture and crude fat contents were observed in the pulp and peel while there were decreases in the moisture, ash, crude protein and crude fibre contents of the seed in the storage days. The vitamin C content of the African star apple fruit pulp, peel and seed was significantly (p˂0.05) different as storage progressed. There was a significant (p˂0.05) difference in mineral content of the African star apple pulp, peel and seed. Greater amount of sodium, potassium and magnesium were detected in the seed while pulp contain higher amount of calcium. The antinutrient composition decreased significantly (p˂0.05) in the pulp, peel and seed as the days progressed. African star apple fruit has a great potential in improving human health and as supplement in food formulation.