Staphylococcus aureus can cause various clinical manifestations. Staphylococcus aureus that is resistant to methicillin, related penicillins and cephalosporins is called methicillin-resistant Staphylococcus aureus (MRSA). The widespread of MRSA is troublesome so a new alternative substance is needed. One of the potential alternative substance is bidara leaf (Ziziphus mauritiana) because it contains tannin and flavonoid. This study aimed to determine whether bidara leaf extract has antibacterial activity against Staphylococcus aureus and MRSA or not. The concentration of bidara leaf extract used are 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%. Disc diffusion method was used and all tests were performed in triplicate. The data was obtained in millimeter by measuring the diameter of inhibition zone. The result for Staphylococcus aureus in positive control (23.67 ± 6.61 mm), negative control (0.00 ± 0.00 mm), 10% concentration (0.00 ± 0.00 mm), 20% concentration (9.09 ± 0.45 mm), 30% concentration (8.90 ± 0.06 mm), 40% concentration (9.58 ± 0.11 mm), 50% concentration (9.69 ± 0.52 mm), 60% concentration (9.98 ± 0.34 mm), 70% concentration (10.05 ± 0.92 mm), 80% concentration (9.35 ± 0.26 mm), 90% concentration (9.77 ± 0.69 mm). The result for methicillin-resistant Staphylococcus aureus in positive control (32.26 ± 1.93 mm), negative control (0.00 ± 0.00 mm), 10% concentration (11.25 ± 1.85 mm), 20% concentration (12.83 ± 3.47 mm), 30% concentration (13.37 ± 3.17 mm), 40% concentration (14.42 ± 3.34 mm), 50% concentration (13.44 ± 2.51 mm), 60% concentration (13.52 ± 2.24 mm), 70% concentration (16.03 ± 3.57 mm), 80% concentration (13.62 ± 2.42 mm), 90% concentration (13.06 ± 2.02 mm). Therefore, bidara leaf extract has antibacterial activity against Staphylococcus aureus and MRSA. The largest and smallest inhibition zone produced against both bacteria is seen at 70% concentration and 10% concentration of bidara leaf extract, respectively.