Cashew leaf (Anacardium occidentale L.) is rich in bioactive compounds such as flavonoids, tannins, glycosides, and terpenoids, which exhibit antibacterial properties. To optimize its application, the leaf extract was formulated into a peel-off gel mask. This study aimed to evaluate both the antibacterial activity of the cashew leaf extract peel-off gel mask against Staphylococcus epidermidis and its physical stability. The extract was obtained through maceration using 96% ethanol as a solvent, and peel-off gel masks were prepared with extract concentrations ranging from 10% to 20%. The antibacterial efficacy of the formulations was assessed using the agar-well diffusion method, while the physical stability of the masks was monitored over a 4-week storage period. Physical evaluations included organoleptic properties, adhesiveness, spreadability, pH, and drying time. Data were analyzed using one-way ANOVA and paired T-tests. Results indicated that higher concentrations of cashew leaf extract corresponded with increased antibacterial activity, adhesiveness, and drying time, while spreadability decreased, and pH became more acidic. The peel-off gel masks demonstrated significant antibacterial activity against Staphylococcus epidermidis, with inhibition zone diameters of 11.25±0.50 mm for Formula 1, 12.50±0.58 mm for Formula 2, and 14.00±0.82 mm for Formula 3. Overall, the peel-off gel masks remained physically stable throughout the 4-week storage period.