Thrush is a disease caused by fungi, one of which is Candia albicans in the mouth and esophagus, as well as inflammation that occurs in the mucosa of the oral cavity. The incidence of cancer sores with the most significant prevalence is 25%. Rosella flower extract has the potential as an antifungal because it contains flavonoids, alkaloids, tannins and saponins. This study aims to determine the effectiveness of rosella flower extract mouthwash in inhibiting Candia albicans and to evaluate the quality of rosella flower extract mouthwash. Formulation of mouthwash with various concentrations of 1%, 3%, 5%, 7% and negative control. Rosella flowers were extracted using the maceration method with 70% ethanol solvent. The antifungal activity test was carried out by the agar diffusion method with disc paper. The results of this study were obtained from the effectiveness of rosella flower extract mouthwash (Hibiscus sabdariffa Linn.) in inhibiting Candida albicans , the best inhibitory effect was a 7% concentration of 12.0 mm mouthwash. The higher the concentration of rosella flower extract, the higher the inhibition of fungal growth. The evaluation of rosella flower extract (Hibiscus sabdariffa Linn.) mouthwash which is closest to the standard mouthwash with a concentration of 3%