One-stage subtotal colectomy is the most radical solution of ileous conditions caused by an obturating tumour of the left half of the colon. The authors report on their experience with this procedure in 10 patients operated in the course of three years. They emphasize the advantages such as oncological radicality, immediate detoxication of the organism, a favourable postoperative course with a low morbidity (10% dehiscences) and lethality (10%), shorter hospitalization period, life of the patients without a stoma, lower costs and satisfactory functional results. For an experienced surgeon, if perfect intensive postoperative care is available, this operation is the method of choice even in very old patients.