The oral cavity is a complex environment colonized by a diversity of microorganisms, some of which are responsible for the development of oral pathologies, namely, Streptococcus mutans and Actinomyces naeslundii [1, 2]. The search for natural alternatives in the prevention and treatment of oral pathologies has significantly increased in recent years, particularly due to the growing bacterial resistance to conventional antimicrobial agents [3]. In this context, the present study aims to analyze endogenous plants, such as chamomile (Matricaria Chamomilla L.) and thermal water, known for their antimicrobial and anti-inflammatory properties [4]. The antimicrobial activity was determined by the Minimum Inhibitory Concentration (MIC) and flow cytometry methods. It was observed that Streptococcus mutans presented an MIC of 31.25 mg/mL, while Actinomyces naeslundii showed an MIC of 3.90 mg/mL. Subsequently, the action of chamomile in synergy with thermal water on bacterial viability was evaluated using flow cytometry. With simultaneous incubation of SYTO9 and propidium iodide (PI), it was observed that approximately 82% of Actinomyces naeslundii presented a positive superlabel (SYTO9⁺/PI⁺), which indicates an alteration in the integrity of the plasma membrane, confirming the toxicity of the chamomile extract in relation to this species. Regarding Streptococcus mutans, approximately 56% of the bacteria, Streptococcus mutans, presented positive labeling for both markers (SYTO9⁺/PI⁺), with this result suggesting a less pronounced toxic effect for this strain. In conclusion, the results highlight the relevant antimicrobial potential of chamomile concerning the two bacterial species analyzed, especially against Actinomyces naeslundii. With these results, we were able to reinforce the viability of this approach using natural extracts as an alternative strategy for the prevention and treatment of oral pathologies.