Cleistanthus collinus is known for being toxic and frequently used for homicidal and suicidal purposes contains three identical compounds, viz. CleistanthinA, B and C (diphyllin glycoside) in addition to other secondary metabolites. This species has a restricted global distribution occurring in India and Sri Lanka. In India, it has been recorded in hills of Himachal Pradesh to Bihar,Andhra Pradesh, Karnataka and Kerala. This is very common in north eastern districts of Andhra Pradesh. The aerial parts of the tree are investigated for phytochemicals and its antimicrobial properties for value addition of this important non wood forest product (NWFP). The bark and leaf powder of Cleistanthus collinus were extractedwith different solvents and quantified with a view to isolate natural compounds with high value and novel properties for better applications.Methanol and ethyl acetate extracts of leaf and barkwere investigated for antimicrobial activity on four species of bacteria Escherichia coli, Bacillus, Staphylococcus, Pseudomonas. The percentage of growth inhibition of the four bacterial species to various concentrations of extracts was calculated and tabulated. The methanol extract as well as ethyl acetate extracts of both bark and leaf were found to inhibit all four species of bacteria. On broader comparison, the methanol extract of leaf was found to be more effective in inhibiting all the four bacterial species compared to methanol extract of bark and ethyl extract of both leaf and bark extracts. Thus it was concluded that the methanol extract possessed the compounds which were capable of inhibiting the growth of human pathogen at very low concentrations.