10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 2 2015 (April - June) Hexane, chloroform, ethyl acetate and methanol extracts of lessThan i greaterThan Azima tetracantha lessThan /i greaterThan were screened for their antimicrobial activity against human pathogenic bacterial and fungal strains. Antimicrobial activity was carried out by disc diffusion method, determination of minimum inhibitory concentrations (MIC), minimum bacterial concentrations (MBC) and minimum fungicidal concentrations (MFC) against three strains of Gram positive bacteria, four strains of Gram negative bacteria and three species of fungi. The antimicrobial activity of various extracts of lessThan i greaterThan A. tetracantha lessThan /i greaterThan showed varied levels of antimicrobial activity against the studied bacterial and fungal pathogens. The mean zone of inhibition produced by all the tested extracts ranged from 6.5±0.20 to 19.1±0.15 mm. The MIC, MBC and MFC values were between 15.6 and 1000 µg/ml. The methanol extract of lessThan i greaterThan A. tetracantha lessThan /i greaterThan showed good antimicrobial activity with the highest mean zone of inhibition (19.1+0.15 mm), lowest MIC (15.6 µg/ml), MBC (31.2 µg/ml) MFC (125 µg/ml) and values followed by other extracts. B. VINOTH AND R. MANIVASAGAPERUMAL Antibacterial activity; Antifungal activity; Azima tetracantha; Successive extracts 613-620