Medicinal plants synthesize a vast array of secondary metabolites that are important for human life. For Medicinal purpose, antimicrobial activity of substances derived from plant extracts has been recognized for many years. The antimicrobial activity of the petroleum ether, chloroform, ethyl acetate, methanol and aqueous extracts of the seeds of Pimpinella anisum L. (Apiaceae) was tested for their potential antimicrobial activities against two Gram positive (Bacillus subtilis, Staphylococcus aureus), three Gram negative (E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) bacteria and against two standard fungi namely Aspergillus niger and Candida albicans using the cup-plate-agar diffusion method. The Petroleum ether, chloroform, ethyl acetate and methanol extracts of P. anisum (1:10 and 2:10) were highly active (30-40 mm) against B. subtilis. The ethyl acetate extract exhibited moderate activity (15 mm) against E. coli and low activity (13 mm) against Ps. aeruginosa. The methanol extract of P. anisum showed high activity (16 mm) against E. coli, low activity (13mm) against Ps. aeruginosa. The methanol extract have variable activity against all test organisms. All the tested organisms were resistant to anise seed aqueous extract. The results were comparable to those of the standard drug gentamicin and nicin.