Herniation of viscera induced by medical intervention has been described in carnivores, yet occurrence of hernias causing wild carnivore mortality, including in bears, remains unknown. We describe an inguinal hernia, intestinal entrapment and rupture, and peritonitis causing mortality in a male American black bear (Ursus americanus). In the autumn of 2014, a free-ranging, adult bear was housed at Virginia Tech's Black Bear Research Center. After 13 days in captivity, the bear showed signs of lethargy and intermittent inappetence consistent with the onset of hibernating behaviors. However, the bear suddenly displayed rapid deterioration and died before medical assistance could be provided. During necropsy examination, a devitalized portion of small intestine was found entrapped in the left inguinal ring. An intestinal perforation was evident near the entrapment area, which caused a subsequent peritonitis. To our knowledge this is the first report of bear mortality due to inguinal herniation with subsequent perforation and peritonitis.