We present a cadaveric case study of an 88-year-old woman with an unusual posterior perineal hernia containing small bowel, rectum, and mesentery. Dissection revealed several loops of the small bowel occupying the presacral space and displacement of the rectum into a large perineal evagination. The intestinal mucosa appeared to have been healthy at the time of death, and we did not find any indication of rectal prolapse. There was also no evidence of past surgery, suggestive of a primary hernia. We conclude this patient had a posterior enterorectal perineal hernia. Suggestions for surgical repair are described.