Osteomyelitis, which is characterized by progressive inflammatory bone destruction and resorption, is a difficult‑to‑treat infection. Staphylococcus aureus (S. aureus) is one of the major causes of this disease. This pathogenic microorganism possesses several characteristics, which facilitate its involvement in the occurrence and progression of osteomyelitis. A cell‑permeable peptide inhibitor of the IκB kinase complex, the nuclear factor (NF)‑κB essential modulator‑binding domain (NBD) peptide, has been reported to block osteoclastogenesis and may be considered a potential strategy for preventing inflammatory bone resorption. However, it remains to be determined as to whether the NBD peptide can regulate inflammation and bone resorption in S. aureus‑induced osteomyelitis. In order to investigate the role of NBD in S. aureus‑induced osteomyelitis, the present study obtained the NBD peptide, and confirmed that it inhibited receptor activator of NF‑κB ligand‑induced osteoclastogenesis in vitro. Subsequently, a bone defect was generated and S. aureus was injected into the mandible of experimental animals, in order to establish an in vivo osteomyelitis model. The present study analyzed the following three experimental groups: Untreated, treated with debridement, and treated with debridement plus NBD peptide administration. The results revealed that treatment with the NBD peptide reduced the bone defect in a 3‑dimensional manner, and reduced bone resorption. To the best of our knowledge, the present study is the first to demonstrate that, in a model of osteomyelitis caused by S. aureus, the NBD peptide serves a role in inhibiting osteolysis and promoting bone remodeling in the direction of osteogenesis. The effects were better than those produced by debridement alone, thus suggesting that it may have promising therapeutic potential in osteomyelitis.