Objective: To investigate the etiology, clinical characteristics and management of spontaneous perforation of the sigmoid colon in elderly patients. Methods: The clinical data of 21 elderly patients with definite diagnosis of spontaneous perforation of the sigmoid colon from November 2007 to October 2012 were retrospectively analyzed. Results: Of the patients, 12 cases were males and 9 were females with an average age of 47 (62–73) years. The majority of these patients were admitted for acute abdominal pain, all of them had experienced habitual constipation of varying degrees, and 3 cases developed septic shock before surgery. In the entire group of 21 patients, only 4 cases were diagnosed as sigmoid colonic perforation, and the misdiagnosis rate was 80.95%. All of the 21 patients underwent Hartmann's procedure and, after surgery, there were still 3 cases who developed septic shock that was resolved after aggressive anti-infective and anti-shock supportive therapies; wound infection and pulmonary infection occurred in 8 and 6 cases respectively, which were cured by anti-infective and symptomatic treatment; 3 cases were complicated by multiple organ dysfunction syndrome (MODS), and one of them was cured after emergent care, while the other 2 cases died from perforation of the retroperitoneal sigmoid colon. Nineteen patients were cured and discharged from the hospital, and their sigmoid colostomy was closed 3–6 months later. Conclusion: The clinical manifestations of spontaneous perforation of the sigmoid colon in old patients are not specific, and abdominal paracentesis, X-ray, and digital anorectal examination are helpful for the diagnosis. Increased understanding of this condition, early diagnosis and intervention including aggressive anti-shock and anti-infective therapy, maintenance of water-electrolyte and acid-base balance, and early surgical and symptomatic treatment, as well as prophylaxis of complications are important to ensure the recovery of these patients.