Intussusception is a rare cause of intestinal obstruction in adult patients, but is common in children. In fact, it accounts for an estimated 1% of all cases of bowel obstruction in adults, although adult intussusception of the large intestine is rare. Sigmoidorectal intussusception, however, is a rare variety with few cases reported in the literature. A mucinous adenocarcinoma, a subtype of adenocarcinoma, is characterized by extracellular mucin production and accounts for between 5% and 15% of the neoplasms of the colon and rectum. Despite the general consensus supporting surgical resections for adult intussuceptions, controversy remains over whether intussuceptions should be reduced before resection. Most cases of colon intussusception should not be reduced before resection because they most likely represent a primary adenocarcinoma. However, prior reduction followed by a resection can be considered for the sigmoidorectal intussusception to avoid inadvertent low rectal cancer sugery. We experienced one case of sigmoidorectal intussusception caused by a mucinous adenocarcinoma of the sigmoid colon in a 79-year-old woman. Abdominal computed tomography demonstrated a sigmoidorectal intussusception. After the end-to-end anastomosis-dilator-assisted reduction, the patient underwent a laparoscopic oncological anterior resection under the impression that a sigmoidorectal intussusception existed. We report a successful laparoscopic anterior resection in a patient with an intussusception caused by a sigmoid malignant tumor.