Intussusception is a common in pediatric age group. But it is rare in adults. And intussusception caused by tumor account for 1% of bowel obstructions in adult. Intussusception is an extremely rare cause of abdominal pain in pregnancy. In particular, cases of Intussusception due to colorectal cancer during pregnancy have never been reported in Korea. Our patient is a 34 years old woman who presented at 14 weeks of her second pregnancy. She presented with right lower abdominal discomfort and intermittent palpable mass which was usually spontaneously resolved. In the MRI study, pathologic asymmetric wall thickening was still noted and ileocolic intussusception was noted, and in colonoscopy, there was ulcerofungating mass around ileocecal valve which may be a leading point of intussusception. Biopsy was done. Pathologic finding was poorly differentiated adenocarcinoma. Under the patient agreement, we performed dilatation and curettage and laparoscopic right hemicolectomy and lymph node dissection. Now she is receiving a FOLFOX chemotherapy.