Antibacterial activity of seed extracts of cumin (Cuminum cyminum L.) was investigated against 10 gram positive and gram negative bacteria. Disc diffusion method was used to test antibacterial activity. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined by using standard procedures. The highest (effective) inhibition zone of 16.67±0.47 mm was found at 250 mg/ml for Escherichia coli. On the other hand, the inhibition zones 15.00±0.82 mm for ethanol, 15.33±0.47 for methanol, and 15.67±0.82 for acetone were found against Bacillus subtilis, Sarcina lutea and Klebsiella pneumonia, respectively. MIC value (20 to 50 mg/ml) and MBC value (40 to 60 mg/ml) were measured against studied bacteria. On the basis of investigation, we can say, cumin seeds could be used as a source of new antibacterial agent for developing drugs to inhibit some human pathogenic bacteria.