Background: One of the main dental and oral health problems that occur throughout the world is dental caries. Cariogenic bacteria such as Streptococcus mutans and Lactobacillus acidophilus are the main microorganisms that cause dental caries. Saliva plays a significant function in maintaining optimal dental health and oral cavity especially because of its components such as pH, flow, and buffering capacity. These three components have a significant role in the initiation and development of dental caries. Gargling is one of the activities that can be done as a prevention of dental caries. Green tea contains the compound Epigallocatechin gallate (EGCG) which is a flavonoid compound that has antioxidant, anti-inflammatory, antifungal, antibacterial, and anticariogenic properties. This systematic review aims to describe the effect of gargling with green tea to prevent dental caries incidents. Method: The method used is a systematic review which is done by searching articles through Google Scholar, PubMed, and ScienceDirect. Discussion: Gargling with green tea regularly can help to increase the pH of saliva. It will help the tooth remineralization process and prevent caries. Green tea contains catechins that inhibit acid formation and reduce the work of the glucosyltransferase enzyme of Streptococcus mutans. The largest catechin content in green tea is EGCG. EGCG can reduce the quantity of Streptococcus mutans. Conclusion: Gargling with green tea is effective in preventing dental caries incidents because it contains catechins, especially EGCG, tannins, and fluoride.