Small bowel diverticulitis is a rare cause of an acute abdomen. Originating from acquired diverticula of the jejunum, less often of the ileum, or Meckel diverticulum, the symptoms are nonspecific, simulating other acute inflammatory disorders, such as appendicitis, cholecystitis or colonic diverticulitis. The diagnosis of small bowel diverticulitis is solely based on radiologic findings, with computed tomography (CT) regarded as the method of choice. In recent years, a number of case reports have described the spectrum of the CT features in acute small bowel diverticulitis and its dependence on the severity of the inflammatory process. Typical findings are an inflamed diverticulum, inflammatory mesenteric infiltration, extraluminal gas collection and mural edema of adjacent small bowel loops with resultant separation of bowel loops. An enterolith is rarely found in an inflamed diverticulum. Complications include abscesses, fistulae, small bowel obstruction and free perforation with peritonitis. Small bowel diverticulitis can be a diagnostic problem if it involves the terminal ileum or Meckel's diverticulum. For preoperative confirmation of the presumed diagnosis of small bowel diverticulitis on CT, an enteroclysis for acquired diverticula or a technetium scan for Meckel's diverticulum should be performed. We present the CT findings in three patients of acute small bowel diverticulitis, two affecting the jejunum and one a Meckel's diverticulum.