&NA;Four additional cases of Ogilvie's syndrome (acute colonic pseudo‐obstruction), representing the first cases described in Italy, are reported. The medical literature concerning the subject is also thoroughly reviewed.Ogilvie's syndrome is an acute massive dilatation of the large bowel without organic obstruction of the distal colon. Three hundred and fifty‐one cases have been described in the literature to date. Eighty‐eight per cent of cases were associated with various extracolonic affections (metabolic and organ dysfunctions, postoperative and posttraumatic states, etc.). Twelve per cent of cases were not associated with known disorders and were defined as idiopathic. The pathophysiology of the syndrome is still unknown. Ogilvie, who first described the syndrome in 1948, suggested an imbalance between the sympathetic and parasym‐pathetic innervation of the colon: this neurogenic hypothesis has been shared by other authors, although explanations may differ slightly. The clinical and radiologic picture closely resembles mechanical obstruction of the large bowel. The most marked dilatation usually takes place in the right colon and cecum: if the distended cecum reaches a diameter larger than 9 to 12 cm, perforation is likely to occur; if perforation occurs, the mortality rate incrases from 25 to 31 per cent to about 43 to 46 per cent. If conservative management fails to control the dilatation and cecal rupture is impending or suspected emergency surgery is indicated, the surgical procedure of choice is dictated by the general conditions of the patient as well as by the intestinal findings: operation may consist of cecostomy, colostomy, or right hemicolectomy or simply emptying the bowel.