Abstract: The total phenolics and the flavonoids contents of stem barks and leaves of Parkia biglobosa harvested at different periods of the year, on 2 different areas of Burkina Faso (Yako and Lèna), were determined. The total phenolics were extracted according to Harborne’s method and also by the means of a soxhlet apparatus. The determination of the phenolics contents was conducted with 8 extracts using tannic acid as standard. The flavonoids contents of the 8 extracts were also determined, using quercetin as a reference substance. The results showed that the total phenolics contents vary significantly all year round at the same area and also from Lèna to Yako. They also revealed that the flavonoids contents of the leaves harvested at Yako ranged from 1.49-1.80% throughout the year. The results also confirmed that the leaves contain more flavonoids than the barks. Antioxidant activity was determined by the means of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. The results showed effectiveness with a radical inhibition ranging from 25.53±3.56-55.449±4.53 mg mL-1. The antibacterial assays on gram positive Staphylococcus aureus showed that the hydroalcoholic extract of stem bark harvested in May at Yako was the most effective of all the extracts.