Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome represents the rare co-occurrence of sterile inflammatory osteoarticular disease in association with a variety of cutaneous manifestations. Oral involvement is uncommon. The etiology of SAPHO is complex and is likely the combined result of infectious, genetic, and immunologic factors. Due to diverse clinical presentations, SAPHO is difficult to diagnose. Here, we describe the case of a 74-year-old man, who had a history of SAPHO syndrome and presented with gingival pustules and sterile diffuse sclerosing osteomyelitis of the mandible. This is the first case report describing neutrophilic mucositis as a feature of SAPHO.