Background: Rectal diverticula are a very rare occurrence compared to diverticula of the colon. They are reported to account for only 0.08% of all diverticulosis. Diverticula of the rectum can be caused by congenital or acquired factors. The majority are asymptomatic, diagnosed incidentally, and require no treatment. The low incidence of rectal diverticulosis may be attributed to the unique anatomical structure and physiological environment of the rectum. However, complications can arise and may necessitate surgical or endoscopic treatment.Case Description: We report the case of a 72-year-old female with a history of diabetes mellitus, hyperlipidemia, and hypothyroidism who presented to the colorectal surgery clinic with symptoms of constipation of nearly a 50-year duration. The patient underwent an anorectal exam under anesthesia which revealed a 3 cm defect in the left levator muscles with herniated rectal wall. A large left lateral rectal diverticulum was diagnosed during the work-up for pelvic organ prolapse on defecography. She underwent robotic assisted ventral mesh rectopexy and recovered uneventfully. After 1 year of follow-up, the patient is asymptomatic, and the control colonoscopy shows no signs of the rectal diverticulum.Conclusions: Rectal diverticula can present in the setting of pelvic organ prolapse and can be safely managed with ventral mesh rectopexy.