Reversal rates following Hinchey III or IV for perforated diverticulitis range as low as 25–71%, despite how negatively colostomy creation impacts quality of life. Appropriate patient identification and timing of reversal, with the majority of reversals occurring around 90 days, is crucial for reducing the risk of a hostile abdomen from dense adhesions. Patients eligible for Hartmann’s reversal may be prehabilitated prior to surgery to optimize their physical condition and postoperative outcomes. In this chapter, the procedural steps of a Hartmann’s reversal will be reviewed. While reversal was traditionally performed with an open approach, the paradigm has shifted to a minimally invasive approach, with single-port laparoscopy recently demonstrating promising results. Various surgical techniques performed for both Hartmann’s procedure and/or reversal will be reviewed as well, including: the decision to mobilize the splenic flexure, to ligate the inferior mesenteric artery (no ligation vs. high/low tie), verification of anastomotic perfusion, perioperative oxygen administration, and types of anastomoses. Finally, postoperative outcomes and complications will be addressed.