Cyanide is a toxic substance that can be lethal to humans and is present in nature in several superior plants, called cyanogenic plants, with the capacity to generate significant amounts of cyanide (CN) from the cyanogenic glycosides (GCs) present in a natural state. Among the most important GCs are linamarin, lotraustralin, dhurrin and amygdalin. Cassava, sorghum, almonds, apricots, peaches, apples, cherries, alfalfa, bamboo, among others, are examples of these plants. The potential to generate CN varies with each plant. This paper reviews the literature related to the amounts of cyanide produced by these plants, their effects on humans, as well as their toxicological implications.