Cases of diverticulosis of the colon continue to increase, especially in the Western countries. In these countries, two-thirds of the population older than 70 years of age are considered to experience this disease. Medical and surgical treatment for diverticulosis actually begun for the complications of diverticulitis and lower gastrointestinal hemorrhage. The first evaluation of complicated diverticular disease is based on patient's history, physical examination, and laboratory data. But all these exams and data can be inaccurate and are often questionable in the diagnoses of many features of the disease. To describe the position, severity, and presence of complications of a detected diverticulum is crucial to its appropriate treatment. The greater part of the patients have mild disease and can be successfully cured medically. Only a small number of patients admit with acute diverticulitis and need urgent surgical intervention. Determining these patients early is crucial to morbidity and mortality reduction. Radiologic examination is important for exact evaluation of the extent of the course of the disease over the last three decades. This article aims to chart the place of the Computed Tomography (CT) imaging procedure in the assessment of acute complicated diverticular disease.