Streptococcus anginosus is a normal flora found in multiple body sites and belongs to the Streptococcus milleri group. It has often been associated with pyogenic infection, such as perio-dontitis, endocarditis, pulmonary abscess and abdominal or cerebral abscess. Also uncommonly, it can cause osteomyelitis. A 42-year-old man was admitted due to gastric ulcer perforation. At 12th hospital day, left humeral osteomyelitis and soft tissue abscess developed. Streptococcus anginosus grew in blood culture. He was treated with intravenous penicillin and surgical debridement of the necrotic tissue which lead to a satisfactory result. We report a rare case of Streptococcus anginosus-induced humeral osteomyelitis and soft tissue abscess.