The invitroantimicrobial activity of Nerium oleander roots bark and leaf extracts were studied against Bacillus pumilus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Aspergillus niger. The chloroform, ethanol and methanol extracts of Nerium oleander showed high activity against all the tested bacteria. None of the crude extracts of the selected plant exhibited activity against Aspergillus niger. These results were compared with the Zones of inhibition produced by commercially available standard antibiotics. The inhibitory effects of extracts are very close and identical in magnitude and are comparable with the standard antibiotics used.