Periodontal disease is an oral health problem, a global concern according to the World Health Organization (WHO). Data from the Global Burden of Disease 2016 indicates that severe periodontal disease ranks 11 in global prevalence and is expected to rise. Periodontal disease, caused by bacterial plaque, is a leading cause of tooth loss, impacting mastication, aesthetics, and quality of life. Plaque, a biofilm of microorganisms, triggers a chronic inflammatory response leading to dysbiosis and clinical disease. Microorganisms like Streptococcus sanguinis and Porphyromonas gingivalis play a crucial role in forming periodontal biofilm, with virulence factors that damage tissues. While chlorhexidine gluconate is effective in removing biofilm, it has long-term side effects. Therefore, natural ingredient-based mouthwashes are being researched. Rosella flower petals (Hibiscus sabdariffa L.) have antibacterial properties inhibiting S. sanguinis and P. gingivalis. They also exhibit antimicrobial, antioxidant, and anti-inflammatory activities. Previous studies found Rosella extract effective in inhibiting biofilm formation of these bacteria compared to chlorhexidine, but its effects in mouthwash formulations are unstudied. The phytochemical, organoleptic, pH, viscosity, antibiofilm activity of various mouthwash formulations containing Rosella petals extract has been evaluated. Rosella extract showed significant antibiofilm activity against both bacteria. The formulations maintained acceptable organoleptic properties, stable pH levels, and consistent viscosity. Higher Rosella concentrations correlated with increased effectiveness. Rosella extract is a promising natural ingredient for mouthwash, providing effective therapeutic antibiofilm activity against periodontal pathogens better than chlorhexidine. Further research is recommended to optimize formulation and assess long-term benefits and safety.