70 patients with complete colonic obstruction requiring emergency surgery were treated at the "Clinique Chirurgicale C" between 1977 and 1984. Carcinoma was the cause of obstruction in 65 cases. Obstruction was situated on the right colon 8 times, on the splenic flexure 13 times, and on the left colon 49 times. In emergency obstruction of the right colon was treated by right hemicolectomy in 6 cases with 0 death. Obstruction of the splenic flexure was treated in 10 cases by simple loop colostomy, twice by resection with ileo-sigmoid anastomosis, 1 by resection without anastomosis with 5 deaths. Obstruction of the left colon was treated by simple loop colostomy in 46 cases. Of the 34 patients who survived after loop colostomy, 26 were reoperated and in 23 cases a resection could be performed with 2 deaths and the colostomy could be closed in a third stage in 20 cases without death. 5 years survival of curative resection was 57%. It is concluded that primary resection is the best treatment for obstruction of the right colon and of the splenic flexure. But three stage resection seems to be a good procedure for obstruction of the left colon with low mortality, low morbidity and good 5 year survival.