Some serious infections due to Group A streptococci (Streptococcus pyogenes, GAS) manifest as primary peritonitis, which traditionally and commonly leads to the selection of laparotomy for initial treatment. We encountered a case in which laparoscopic surgery proved effective in treating primary peritonitis due to GAS. The patient was a 30-year-old woman transported via ambulance to our hospital with complaints of fever, abdominal pain, diarrhea, and vomiting on day 5 after a miscarriage. Diagnostic laparoscopy was performed under a presumptive diagnosis of acute generalized peritonitis. Accumulation of purulent ascites was found in the peritoneal cavity, but no primary lesion was identified. Peritoneal lavage and drainage were performed, and the surgery was concluded. Postoperatively, GAS were detected in blood, ascites, and vaginal discharge cultures, and primary peritonitis due to GAS was diagnosed. Antibiotics were switched to ampicillin sodium and clindamycin phosphate, and her condition started to improve. When primary peritonitis due to GAS is suspected, laparoscopic surgery can be considered for initial treatment.