The study was conducted to analyze the antibacterial activity of Plectranthus argentatus plant leaves. The plant sample was extracted using methanol and water in the ratio 9:1. From the study the plant Plectranthus argentatus was found to inhibit the growth of Escherichia coli with a zone of inhibition of 11.67 ± 0.882, Serratia liquefaciens zone of inhibition of 12.67 ± 0.667, Bacillus cereus 28.00 ± 1.154 and Proteus vulgaris 11.00 ± 0.577. The bacteria which had a zone of inhibition of less than 8 mm were termed to be unsusceptible. The data collected and documented in this paper is a scientific justification that the plant Plectranthus argentatus can be used to treat against various diseases caused by E.coli, S. liquefaciens, Bacillus cereus and Proteus vulgaris. However, more scientific data needs to be provided to indicate the mode action of the plant active compounds against the pathogens.