Abstract: This study was conducted to measure the antimicrobial activity of Jatropha curcas (Linn.) root bark extract against Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Candida albicans. The antimicrobial activity was carried out using agar diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) was done using broth diffusion method. Broth extracts were found active against all the tested organisms with zone of inhibition ranging from 15 mm – 20 mm and 15 mm – 18 mm for ethylacetate and methanol extracts respectively and 50 – 100 mg/ml MBC/MFC. The ethylacetate extract was found to be bactericidal to all the organisms tested. This result indicates the wide spectrum activity of this plant (extract) against micro organisms and can be used to treat topical ailments (infectious diseases).