There is a growing trend of consumer preference for the use of natural food preservatives either to prevent the growth of food-borne pathogens, or to delay the onset of food spoilage. In this investigation, an in-vitro screening method was used to determine the antibacterial efficacy of a 10% w/v suspension of the natural leaves of the herb culantro (Eryngium foetidum), against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Salmonella Typhimurium. The apparent sensitivity of the gram-positive bacteria and resistance of the gram-negative bacteria were distinct. Significant antibacterial activity was evident against S. aureus and B. subtilis, but no apparent antibacterial activity was evident against E. coli and S. Typhimurium. There was approximately 100% kill for both S. aureus and B. subtilis. The results obtained from this investigation suggest that culantro leaves can potentially be used as a food preservative, by increasing the safety and extending the shelf life of food products.