The oil of the seeds, petroleum ether and methanol extracts of the whole plant of Cannabis sativa belonging to the family Cannabinaceae were screened for their antimicrobial activity against two Gram positive organisms (Bacillus subtilis, Staphylococcus aureus), two Gram negative organisms (Escherichia coli, Pseudomonas aeruginosa) and two fungi namely Aspergillus niger and Candida albicans using the cup plate agar diffusion method. The oil of the seeds of Cannabis sativa exerted pronounced antibacterial activity (21 - 28 mm) against Bacillus subtilis and Staphylococcus aureus, moderate activity (15 mm) against Escherichia coli and high activity (16 mm) against Pseudomonas aeruginosa and inactive against the two fungi tested. The petroleum ether extract of the whole plant exhibited pronounced antibacterial activity...