Diverticulosis of the colon is frequently found on routine colonoscopy, and the incidence of diverticular disease and its complications appears to be increasing. The role of colonoscopy in managing this disease is still controversial. Colonoscopy plays a key role in managing diverticular bleeding. Several techniques have been effectively used in this field, but band ligation seems to be the best in preventing rebleeding. Colonoscopy is also effective in posing a correct differential diagnosis with other forms of chronic colitis involving colon harbouring diverticula (in particular with Crohn's disease or Segmental Colitis Associated with Diverticulosis). The role of colonoscopy to confirm diagnosis of uncomplicated diverticulitis is still under debate, since the risk of advanced colonic neoplasia in patients admitted for acute uncomplicated diverticulitis is not increased as compared to the average-risk population. On the contrary, colonoscopy is mandatory if patients complain of persistent symptoms or after resolution of an episode of complicated diverticulitis. Finally, a recent endoscopic classification, called Diverticular Inflammation and Complications Assessment (DICA), has been developed and validated. This classification seems to be a promising tool for predicting the outcome of the colon harboring diverticula, but further, prospective studies have to confirm its predictive role on the outcome of the disease.