Pancovia laurentii (De Wild.) Gilg ex De (Sapindaceae) is a plant species of the spontaneous flora of Central Africa, which grows easily in the Republic of Congo. It produces very succulent edible fruits. The evaluation of phenolic compounds and antioxidant activity in the pulp and seed of the fruit during its maturation was done by spectrophotometer. The results reveal the increase of total polyphenols, total flavonoids and anthocyanins in the pulp and seed of the fruit during maturation. Flavonoids accumulate more in the seed than in the pulp. At taste maturity, the seed with 400.85 mg EQ/DM is richer in flavonoids than the pulp which has 322.26 mg EQ/DM. Polyphenols and anthocyanins accumulate more in the pulp than in the seed with respectively 432.8 mg EAG/mg DM for polyphenols and 157.50 mg/mL for anthocyanins. The pulp and seed presented a DPPH radical scavenging activity. The antioxidant activity increases during maturation. It is greater than 50%, particularly in the pulp with 0.25 mg/mL and in the seed with 0.37 μg/mL at taste maturity. These results show the existence of a good linear correlation between the content of total polyphenols, total flavonoids, anthocyanins and the antioxidant power of the pulp and seed of the fruit during maturation. With these contents, the fruit can be considered as a potential source of natural antioxidants.