Calcaneonavicular coalitions are an important cause of adolescent foot pain and deformity. The congenital condition is characterized by an aberrant osseous, cartilaginous, or fibrinous union of the calcaneal and navicular bones. Calcaneonavicular coalitions are the most common form of tarsal coalitions identified within epidemiologic studies. A thorough understanding of this clinically significant entity is important for restoring joint motion and preventing long-term disability.