Traumatic dislocation of an intact tarsal navicular is an uncommon injury. In this article, we report a case of open medial navicular dislocation in a 45-year-old man. The injury was managed with open reduction and stabilization with Kirschner wires within the acute period. Ten months after injury, the patient developed avascular necrosis of the navicular and exhibited progressive collapse of the medial midfoot. He underwent naviculocuneiform arthrodesis 1 year after the index surgery. Two years after fusion, he was pain-free and ambulating independently. Successful treatment of midfoot fractures and dislocations requires an intimate understanding of anatomy, biomechanics, and both short- and long-term sequelae of injury.