&NA;Results after operations for acute obstruction of the large intestine due to cancer were analyzed during a 10‐year period and compared with the results after operations for nonobstructive tumors during the same period. The following conclusions could be deduced: 1) Cancer is more often obstructive in the colon than in the rectum. Cancers of the splenic flexure are relatively more often obstructive than cancers in other parts of the colon. 2) Postoperative morbidity (and probably mortality) is higher and the five‐year survival shorter in patients with obstructive cancers of the large intestine than in those without obstruction. Obstructive Dukes' A tumors are very few. 3) The early morbidity and mortality after acute cecostomy are probably not higher than after acute transversostomy, if the cecostomy wound is left open. The cecostomy carries a risk of peritoneal contamination. 4) Cecostomy does not relieve obstruction in 5‐10 per cent of the patients, while transversotomy seems always to be effective. Emergency exploratory laparotomy for obstructive cancer of the large bowel instead of a blind cecostomy reduces the number of patients who need two operations by 10 per cent. 5) Hernias are frequent at the sites of previous spontaneously closed cecostomies. 6) Antibiotic bowel preparation seems not to be effective shortly after decompressive colostomy.