Since the 1970s it has been postulated that dietary fibre is a protective factor against colorectal cancer. Several epidemiological studies have been performed following different designs (correlation studies, case–control, cohort) and overall they have supported the hypothesis of a benefit of dietary fibre. However, a few intervention trials have not demonstrated the preventive role of dietary fibre on the occurrence of adenomatous colorectal polyps. Nevertheless, there are multiple animal experimental studies that support the role of fibre in the prevention of colorectal cancer. In the present review, the most important contributions to this controversial question are revised. Finally, it is recommended to continue encouraging an increase in the daily consumption of fibre, since it probably plays an important role in the prevention of colorectal cancer, together with other beneficial effects.