Purpose: To identify factors significantly associated with the mortality of patients with left colonic perforation, and to compare the outcome of Hartmann’s procedure (HP) and primary repair (PR) or primary anastomosis (PA) in patients with left colonic perforation without factors associated with mortality. Methods: This retrospective study included patients who underwent surgery for left colonic perforation from January 2009 to February 2018. Preoperative factors related to postoperative mortality, including vital signs, laboratory findings, and intraoperative findings, were analyzed by type of operation. The chi-square, Fisher exact, and Mann-Whitney U-tests were used to analyze the data. Results: Ninety-one patients were included (36 men, 55 women), and 15 (16.5%) died postoperatively. Prognostic factors were age, leukopenia, thrombocytopenia, bleeding tendency, acute kidney injury, hemodynamic instability, and the existence of feculent ascites. Leukopenia and longer operative time were independent risk factors for mortality. Seventy-nine patients did not have leukopenia and 30 of these patients who underwent PR without diversion were excluded from the subanalysis. HP was performed in 30 patients, and PR with diversion and PA with or without diversion were performed in 19. Compared to the other operative methods, HP had no advantage in reducing hospital mortality (P=0.458) and morbidity. Conclusion Leukopenia could be an objective prognostic factor for left colonic perforation. Although HP is the gold standard for septic left colonic perforation, it did not improve the hospital mortality of the patients without leukopenia. For such patients, PR or PA may be suggested as an alternative option for left colonic perforation.