Several reports over the past 15 years describe severe group A streptococcal infections causing septic shock, soft-tissue necrosis, and multiple organ failure; a phenomenon known as streptococcal toxic shock-like syndrome (TSLS). However, primary peritonitis associated with TSLS is rare. We report the case of a 40-year-old man admitted with pain in both thighs, hypotension, and severe abdominal pain. His daughter had been diagnosed with streptococcal pharyngitis 3 days earlier. We performed an emergency laparotomy for peritonitis, and culture of the ascites was positive for group A beta -hemolytic streptococcus (GAS). Further serotyping of the isolated GAS strain revealed the T-type 22 and the pyrogenic exotoxin gene, spe-C. The criteria for TSLS were clearly met, including the isolation of GAS from ascites, hypotension, liver failure, renal failure, coagulopathy, myositis, and a generalized erythematous macular rash with desquamation.