Three decades ago, the observations of Trowell and Burkitt gave rise to the "fibre theory", in which it was contended that there was a link between the consumption of a diet rich in fibre and non-processed carbohydrates and the level of protection against many of the "first world diseases" such as constipation, diverticulosis, cancer of the colon, diabetes, obesity and cardiovascular disease. Since that time, numerous studies have been presented to analyze the relationship between fibre and disorders of the gastrointestinal tract and other processes with severe health implications. The present revision looks at the experience accumulated over this period regarding the importance of the consumption of fibre for certain phatologies. It not only deals with the epidemiological relationship existing between fibre intake and the development of diseases such as cancer of the colon or cardiovascular disorders but also reviews the interest of fibre a therapeutic agent, in view of the current information available on its different mechanism of action. Thus the possibility of using soluble fibre has taken on renewed interest for the treatment of inflammatory intestinal disease, for control of diarrhoea, in irritable bowel syndrome or no modulate the concentrations of glycaemia or cholesterol. Three is a discussion of the discrepancies found between the consumption of fibre and diverticular disease, the treatment of constipation and the association with obesity and cardiovascular disease. Despite the accumulated evidence on the consumption of fibre, there is currently no consensus as to recommendations on what type of fibre and the optimal amount that should be consumed. A high fibre intake (> 25-30 g/day) based on a variety of food sources (fruit, vegetable, legumes, cereals) is the only way to avoid many of the disorders mentioned. The consumption of a particular type of fibre (soluble or insoluble) is limited to the treatment of certain processes, because its individual relationship with many disorders is still pending determination.