This study investigated the phytochemical composition, antimicrobial activities and toxicological properties of methanolic whole plant extract of Phyllanthus amarus . Phytochemical analysis revealed the presence of saponins, tannins, flavonoids, terpenoids and cardiac glycosides. Antimicrobial sensitivity test using fourteen human pathogenic microorganisms showed that Phyllanthus amarus has bactericidal effect on four pathogens namely Proteus vulgaris , Micrococcus luteus , Bacillus polymyxa and Escherichia coli . The extract also demonstrated significant inhibitory effect on Corynebacterium pyrogenes , Bacillus subtilis , Clostridium sporogenes , Klebsiella pneumonia and Staphylococcus aureus but the microbes were able to recover after a few hours. Administration of Phyllanthus amarus extract to rats for 14 days caused growth depression with no significant change (P