Colitis cystica profunda is a rare and infrequent benign lesion of the colon and rectum-sigmoid colon. Histologically, it is characterized by glandular cystic dilatation with mucin production and extension through the colonic wall, penetrating the muscularis mucosae, submucosa, and even the muscularis propria. We report a case of colitis cystica profunda that occurred in a radiation-induced colonic stenosis. A 66-year-old woman with a history of stage IA2 squamous cell carcinoma of the cervix, treated with conization in addition to simultaneous chemotherapy and radiotherapy. External beam radiation with cobalt60 was administered at specific doses. 27 years later, she presented diarrheal stools approximately 7 times with abdominal distension. On physical examination, a tumor was found in the sigmoid colon; she was referred to a third-level hospital; a colostomy in the left transverse loop and sigmoidectomy were performed. In the pathological analysis, a Rectosigmoidectomy product was received and a zone of stenosis with shiny mucosa and thickening of the wall was found. Microscopically, submucosal cysts filled with mucin of variable size were found, covered by a layer of epithelium without atypia that infiltrated the colonic wall. Colitis cystica profunda is a benign non-neoplastic disease. Knowledge of this pathological entity associated with a history of radiation is important since there are few cases reported in the literature.