Dipterocarpus alatus has been used for the treatment of external wounds and skin diseases in traditional medicine. Staphylococcus aureus is a major pathogen for human superficial skin infections. This study determined the antibacterial effects of D. alatus twig crude extracts against methicillin-sensitive/resistant S. aureus (MSSA and MRSA) in vitro and in vivo. Several organic solvents were used to extract D. alatus twig. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the D. alatus extracts for MSSA and MRSA were investigated using broth micro-dilution assays. The most potent extract was studied in a mouse superficial wound model with MRSA infection. The ethyl acetate-methanol extract of D. alatus, MeOH(EtOAc), showed the lowest MIC and MBC values (0.390 and 0.781 mg/mL, respectively) against both MSSA and MRSA compared to the other extracts. MRSAinfected mouse superficial wounds showed increased transepidermal water loss (TEWL), mast cell accumulation, and MRSA colony numbers. Treatment with MeOH(EtOAc) extract (20 mg/mL), or MeOH(EtOAc) emulgel (20-40 mg/mL), 100 µL applied daily for 10 days, reduced TEWL values, mast cell accumulation, and MRSA colony numbers in wounds compared to the non-treated group. The wounds of the MeOH(EtOAc) extract and MeOH(EtOAc) emulgel treatment groups were healed on day 8 while the wounds of the dipterocarpol and tetracycline treatment groups were not. Therefore, MeOH(EtOAc) extract or MeOH(EtOAc) emulgel are good candidates for a topical product to treat ulcerated wounds with MRSA infection.