The antibacterial effect of Azadirachta indica against Pseudomonas aeruginosa, Klebsiella ozanae, Staphylococcus aureus and Escherichia coli was determined using the agar cup plate technique. The phytochemical components of A. indica showed the presence of saponin and phlobatanin and the absence of alkaloids, tannins, phenolics, glycosides, flavonoids and triterpenes. The result showed that the test organisms were susceptible to 500mg/ml, 50mg/ml and 5mg/ml of the plant extract. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The result showed that the MIC and MBC were 5mg and 50mg respectively for Pseudomonas aeruginosa, Kl. ozanae, Staphylococcus aureus and Escherichia coli. The result of the study suggests that extracts of A. indica could be suitable for the treatment of various infections caused by P. aeruginosa, K. ozanae, S. aureus and E. coli.