BACKGROUND: Plants have a diverse variety of bioactive compounds such as tannins, alkaloids, flavonoids, carbohydrates and steroids among many others that can offer significant physiological actions in the human body. Phytochemicals are naturally occurring chemical, biological and active compounds found in plants that are of benefit to human health apart from those that act as macronutrients and micronutrients. A. heterophyllus (Jackfruit) belongs to the family Moraceae. Jackfruit tree is native to India and is popular in several tropical and sub-tropical Countries. OBJECTIVE: The aim of this study is to determine the phytochemical constituents, antioxidant properties and gas chromatography mass spectroscopy (GC-MS) of the fruit peel of A. heterophyllus extracts using three different solvents. METHODS: Artocarpus heterophyllus fruits were collected from University of Ibadan botanical garden, identified at the Forestry Research Institute of Nigeria, Oyo State. The peel was extracted and dried at 35 ℃. Qualitative method and Gas Chromatography Mass Spectroscopy were used to determine the phytochemical and bioactive compounds present in the plant, whereas¬¬¬¬¬¬ 2, 2, Diphenylpicryl-1-hydrazyl (DPPH) was used for the antioxidant analysis. RESULTS: Secondary metabolites such as flavonoids, phenols, alkaloids, glycosides, saponins, tannins, steroids, and Terpenoids were present based on the solvents while anthraquinnes were absent. Flavonoid and phenol were abundant in the three extracts while saponin was moderate. Eight chemical compounds were observed in the plant extracts. Major bioactive components with highest and lowest retention peak were (65.55 %) bis(2- ethyl hexyl) phthalate and (6.06 %) Cis- 13(2- ethylhexyl)phthalate respectively. Antioxidant activity increased with increase in concentration of which acetone extract had the highest DPPH (75.00 %) at 100 μg/ml. CONCLUSION: The fundamental means of the usage of medicinal plants for medicine is due to their bioactive properties which are used as substrates for biochemical and enzymatic reactions. Phytochemical derivatives have antiviral, anti-inflammatory, anti-oxidant, immunomodulatory, anticancer, antimicrobial, antitumor, analgesic and many other properties harbor in them.