Aims: Chemical mouthwash has been used for ages as one of the oral hygiene practices, but due to its side effects, mouthwash formulated from plants has become a better alternative. Andrographis paniculata (AP) is an herb plant known for its antibacterial effects. Thus, this study was aimed to compare the antibacterial activity of AP with commercial mouthwash and to observe the stability of mouthwash formulated from AP. Methodology and results: Aqueous extract of AP was used to prepare herbal mouthwash. The antibacterial activity of AP mouthwash and three commercial types of mouthwash, namely Colgate Plax, Oral B and Listerine, were determined by minimum inhibitory concentration (MIC) through broth dilution method and minimum bactericidal concentration (MBC) against selected oral pathogens; Staphylococcus aureus, Streptococcus mutans and Streptococcus sobrinus. The AP mouthwash was stored for six months and a year at three different storages to assess its stability and microbial contamination by the pour and drop plate method. The results indicated that Colgate Plax and AP mouthwash have the best antibacterial activity compared to two other commercial types of mouthwash with an inhibition percentage of 95.96% at 15.63 mg/mL for S. aureus (Colgate Plax) and 168.45% at 62.5 mg/mL for S. aureus, 93.75% at 7.81 mg/mL for S. mutans and 98.51% at 7.81 mg/mL for S. sobrinus (AP mouthwash). The parameters measured remained unchanged during storage except at room temperature, while the pH level ranged from 6.72 to 7.45. The AP mouthwash showed stable sterility throughout the study. Conclusion, significance and impact of study The AP mouthwash shows good antibacterial activity against oral pathogens and is almost similar to other commercial mouthwashes and stable to be used for up to a year. In addition, it has excellent potential as an alternative herbal mouthwash in treating oral pathogens effectively.