10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 4 2013 (October - December) The aim of my research was to screen secondary metabolites and antimicrobial activities of methanolic extracts of the leaves lessThan i greaterThan lessThan /i greaterThan lessThan i greaterThan Vernonia amygdalina lessThan /i greaterThan and lessThan i greaterThan Plantago lanceolata, lessThan /i greaterThan and acetone extracts of the leaves lessThan i greaterThan Rosmarinus officinalis lessThan /i greaterThan and lessThan i greaterThan lessThan /i greaterThan lessThan i greaterThan Thymus schimperi lessThan /i greaterThan against two bacteria ( lessThan i greaterThan Staphylococcus aureus lessThan /i greaterThan and lessThan i greaterThan Escherichia coli) lessThan /i greaterThan and two fungi lessThan i greaterThan (Aspergillus niger and lessThan /i greaterThan lessThan i greaterThan Fusarium oxysporum) lessThan /i greaterThan using paper disc diffusion method. Phytochemical screening lessThan b greaterThan lessThan /b greaterThan of the extracts revealed the presence of alkaloids, flavonoids, saponins, steroids, tannins, phenolic compounds, anthraquinones, cardiac glycosides and triterpenes in the plants investigated. The plant extracts were found to be more effective on bacteria than fungi. The bioassay has indicated that the inhibition effect of the extracts was proportional to the concentration. The acetone leaf extracts of lessThan i greaterThan Rosmarinus officinalis lessThan /i greaterThan possess higher antibacterial properties than lessThan i greaterThan Vernonia amygdalina, Plantago lanceolata lessThan /i greaterThan and lessThan i greaterThan Thymus schimperi. lessThan /i greaterThan Phytochemical investigation results showed that the highest antibacterial potential of lessThan i greaterThan Rosmarinus lessThan /i greaterThan lessThan i greaterThan officinalis lessThan /i greaterThan may be attributed to flavonoids, phenolic compounds and triterpenes. KESATEBRHAN HAILE ASRESSU Phytochemical screening, plant extracts, medicinal plants, antimicrobial activities 326-333