Anthrax is an acute infectious disease caused by Bacillus anthracic. Gastrointestinal anthrax is considered as a rare condition in pregnancy, and there are few reports describing its complication and treatment procedure. Meanwhile, there is no article reporting successful treatment of a pregnant woman; however, we have reported a successful treatment of gastrointestinal anthrax in a pregnant woman. In this study, we reported a 38-years-old pregnant woman who was referred to the hospital with abdominal pain and persistent hemorrhagic diarrhea. Suzerain operation was also used, and laparotomy showed necrotic gangrene in colon. After the first surgery, the patient showed left lower quadrant abdominal pain (left lower quadrant collection), and drainage was performed during the second surgery. Finally, after 20 days, the patient was recovered and discharged from the hospital in a very good condition. Gastrointestinal anthrax during pregnancy is a very rare condition. In this study, we reported a patient with gastrointestinal anthrax who was recovered by a suitable treatment.