Andrographis paniculata Nees, a member of the family Acanthaceae is a plant commonly used by the local people, for the treatment of common cold, liver diseases, snake bite and some skin infection. The aerial part of the plant was screened for their phytochemical properties and antimicrobial activity. Antimicrobial activity of leaf extract of Andrographis paniculata, was studied using different solvent like chloroform, methanol, petroleum ether and water against bacterial strains like Bacillus subtilis, Escherichia coli by disc diffusion method. Methanolic extract showed maximum inhibitory action against Escherichia coli and Bacillus subtilis respectively. Results of the phytochemical screening showed that steroids, phenols, terpenoids, alkaloids, saponins, flavonoids were the active compounds present in the plant. The plant is traditionally used for the treatment of antibacterial, antioxidant, antidiabetic, antipyretic, hepatoprotective and several infectious diseases ranging from malaria to dysentery. The medicinal value of this plant is due to the presence of active ingredients viz andrographolide and neoandrographolide which are derivatives of diterpenoids. It is a potent scavenger of a variety of reactive oxygen species including superoxide anion, nitric oxide, hydrogen peroxide. The anti-oxidant activity was determined by DPPH (2, 2-diphenyl-1-picrylhydrazyl) method. Total antioxidant capacity were determined spectrophotometrically.