Pteridium aquilinum, popularly known as Bracken fern, is a widely distributed plant which is usually consumed as food by many species. In this article, the toxic principles and some aspects of toxicology related to disturbances of development, which occur when P. aquilinum is used as food by animals (cows, sheeps, horses, pigs, rats, etc.) and humans, were analyzed. It has been concluded that P. aquilinum is an important plant and that its harmful effects could be investigated in future investigations.