Diverticulosis is a very common condition. Around 20% of the carriers of diverticula are believed to suffer from diverticular disease during their lifetime. This makes diverticular disease one of the clinically and economically most significant diseases in gastroenterology. The etiopathogenesis of diverticulosis and diverticular disease is not well understood. Epidemiological studies allow defining risk factors for the development of diverticulitis and its complications. A comprehensive literature search was performed and the current knowledge about risk factors for diverticulitis and associated conditions reviewed. Besides non-controllable risk factors like age and sex, lifestyle factors like food, drinks and physical activity, drugs are described to increase or decrease the risk to develop diverticulitis or to suffer from complications. The recognition of risk factors for the development of diverticular disease or even complicated disease like lifestyle habits or medication is crucial for patient management.