Background: Streptococcus mutans is the main causative agents of dental caries by developing biofilm and increase adherence activity. Dental caries have becoming more common due to antibiotic resistance towards Streptococcus mutans. Spilanthes acmella is well-known as anti-toothache plant with high medicinal usages. It has been recognized as an important medicinal plant with high demand worldwide. Therefore, the objective of this study is to establish antimicrobial activities, including anti-biofilm and anti-adherence activity of Spilanthes acmella on cariogenic Streptococcus mutans. Methods: Spilanthes acmella leaves extracts were prepared by serial extraction with n-hexane, dichloromethane, acetone and methanol. Antibacterial activities of these extracts were conducted using disc diffusion assay, anti-biofilm and anti-adherence activities methods. Results: The result indicates that n-hexane and methanol leaves extracts are endowed with anti-streptococcus activity. Both methanol and n-hexane extracts inhibit moderately Streptococcus mutans growth as indicated in the disc diffusion assay. Methanol and a n-hexane extracts inhibit the biofilm formation and adherence activity of Streptococcus mutans. Conclusion:This study highlights the potential of Spilanthes acmella leaves extract as a new promising anti Streptococcus mutans agents.