Medicinal plants remain the feasible source of new compounds for drug development process. The natural products provide clues for the synthesis of new structural types of antimicrobial and antifungal chemicals that are cost effective and relatively safe for man. The aim of this study was to determine the antibacterial activity of the methanol extract of Jatropha gossypiifolia leaf on Escherichia coli and Staphylococcus aureus. Jatropha gossypiifolia leaves were dried and extraction of phytoconstituents was done following standard procedures. Antimicrobial susceptibility test was carried out on the selected clinical isolates using agar well diffusion technique. The minimum inhibitory concentration and the minimum bactericidal concentration were determined following standard techniques. Results of this study revealed the presence of phenols, tannins and flavonoids. The methanol extract of Jatropha gossypiifolia leaves was active against Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentration (MIC)
of the methanol extract Jatropha gossypiifolia leaves against Escherichia coli was 200 mg/mL and the minimum inhibitory concentration (MIC) of the methanol extract Jatropha gossypiifolia leaves against Staphylococcus aureus was 50 mg/mL. This study confirmed the folk medicine reports of the activity of Jatropha gossypiifolia leaves on some pathogens. It is therefore recommended that other parts of Jatropha gossypiifolia plant should be tested for their antimicrobial activity