Injuries from contact with cactus plants are not uncommon in the southwestern United States and other arid landscapes. Most often, accidental encounters with sharp spines and barbs result in little more than mechanical damage to the skin and soft tissues with minor pain and irritation. Although cactus spine penetration into the skin has been reported to be a stimulus for cutaneous granuloma formation, our review of the published literature did not reveal any potentially life-threatening injuries from such insults. We present a unique case of a penetrating cactus spine to the anterior mediastinum in a child which required surgical extraction.