Polyphenols from four medicinal plants of Burkina Faso, Combretum micranthum, Khaya senegalensis, Pterocarpus erinaceus and Sida acuta, were screened for their antioxidant and antimicrobial activities against pathogenic bacteria. The medicinal plants displayed different polyphenols contents and antioxidant activities. The bark of P. erinaceus had the highest antioxidant activity. Some microorganisms were susceptible to polyphenol extracts with minimal bactericidal concentration values between 20 and 2000 mg/ml while other microorganisms appeared to be resistant to the extracts. Microbicide and microbiostatic activities of the extracts were dependent on the type of strains. Results suggest that these plants are not only interesting sources for antimicrobial activities but also potential sources of phenolic antioxidants.