Most Synthetic drugs have several side effects when administered and the cost of synthesizing them is an expensive endeavour. One alternative is to use herbal medicines. Guyana has an abundance of diverse flora which has been receiving attention in this area. However, much more research needs to be done. The antibacterial activity of natural spices (Tumeric, garlic, onion, celery and cinnamon) was investigated against E. coli, S. aureus, K. pneumoniae and P. aeruginosa and was compared with synthetic antibiotics (Tetracycline, Clindamycin and Ceftriazone) at three different concentrations of 10%, 50% and 100%. The Disc Diffusion Assay was used to investigate the antimicrobial potency of the synthetic drugs and herbal medicines under aseptic conditions. The synthetic drugs were prepared at different concentrations of 10%, 50% and 100%, whereas the extract was investigated at 100% concentration. Experiments were done in triplicates and the diameter of zone of microbial inhibition (DZOI) was measured and expressed as the mean with standard deviation (SD). The precision of comparisons (e.g. 95% confidence intervals) and Area of Zone of Inhibition, AZOI was also computed. Selected microorganisms were also tested against a reference standard antibiotic, Ampicillin and Nystatin. For the synthetic drugs, the highest Area of Zone of Inhibition, AZOI of 1566.4 mm2 was induced by Clindamycin against S. aureus at 50% concentration whereas the lowest AZOI of 245.09 mm2 was induced by P. auriginosa at 10% concentration. For the herbal extracts, the highest AZOI of 1256.6 mm2 was induced by the onion extract versus K. pneumonia whereas the lowest AZOI of 50.3 mm2 was induced by the Tumeric extract against E. coli. Antimicrobial selectivity was also observed for both synthetic and herbal medicines. For example, for tetracycline against S. aureus, AZOI of 1093.92 mm2 was obtained whereas against P. auriginosa, AZOI of 530.67 mm2 was observed. Garlic exhibited AZOI of 139.49 mm2 against E. coli whereas a value of 78.5 mm2 was obtained against P. aeruginosa.