Smoking can cause disruption of oral microbiota which may lead to decrease availability of oxygen in the mouth and increased acidity of saliva, making it a more suitable environment for the growth of bacteria and acid-tolerant microbes. In this study, the researchers used strains of Lactobacillus casei Shirota and Lactobacillus paracasei obtained from commercial probiotic drinks. Agar overlay method was used to test the antibacterial effects of both Lactobacillus spp. against smoking-associated oral pathogens like Staphylococcus aurues, Streptococcus mutans, and Serratia marcescens. The experiment was done in three trials, zone of inhibition was measured and statistical treatment was employed to determine its significance. Both Lactobacillus spp. appeared to be most potent against Streptococcus mutans. Moreover, L. paracasei showed a greater zone of inhibition than that of L. casei Shirota, with a mean value of 7.67 mm, 8 mm and 6.33 mm in Staphylococcus aureus, Streptococcus mutans and Serratia marcescens respectively. Nevertheless, both Lactobacillus spp. was both resistant and is only capable of inhibiting the growth of the pathogens not necessarily kills them, making them inferior with the positive control used, Imipenem.