IntroductionThis case series illustrates the clinical presentation and radiological findings of two patients in whom the diagnosis of a Giant Colonic Diverticulum (GCD) was histologically confirmed. We also discuss the pathogenesis and differential diagnosis.Case presentationIn one case, the patient had no previous large bowel symptoms and intra operatively no other colonic diverticula were found. Both were treated with surgical resection.ConclusionThe preoperative diagnosis of GCD is made radiographically, and the importance of the early recognition of radiological findings, especially in asymptomatic disease, is emphasised.