Fungal (Aspergillus and Penicillium spp.) and yeast (Saccharomyces and Candida spp.) cultures were more sensitive to cumin volatile oil and cuminaldehyde than bacteria. Among Gram-negative bacteria, Escherichia coli was the most sensitive to the volatile oil while Pseudomonas aeruginosa was the most resistant. Staphylococcus aureus had an MIC almost double that of all other Gram-positive species tested, while the fungi had MIC values 10 to 20 times lower than those of the bacteria.