Diverticular disease (DD) of the colon represents the most common disease affecting the large bowel in western countries. Its prevalence is increasing. Recent studies suggest that changes in gut microbiota could contribute to development of symptoms and complication. For this reason antibiotics play a key role in the management of both uncomplicated and complicated DD. Rifaximin has demonstrated to be effective in obtaining symptoms relief at 1 year in patients with uncomplicated DD and to improve symptoms and maintain periods of remission following acute colonic diverticulitis (AD). Despite absence of data that supports the routine use of antibiotic in uncomplicated AD, they are recommended in selected patients. In patients with AD that develop an abscess, conservative treatment with broad-spectrum antibiotics is successful in up to 70% of cases. In patients on conservative treatment where percutaneous drainage fails or peritonitis develops, surgery is considered the standard therapy. In conclusion antibiotics seem to remain the mainstay of treatment in symptomatic uncomplicated DD and AD. Inpatient management and intravenous antibiotics are necessary in complicated AD, while outpatient management is considered the best strategy in the majority of uncomplicated patients.