There are various osseous pathologies that afflict the tarsal navicular. These range from stress fractures and coalitions to overt fractures. In certain instances there is an interruption of its vascular supply. If this occurs in childhood, it is called Koehler's disease. Spontaneous osteonecrosis of the navicular in the adult is a rare entity and is known as Mueller-Weiss syndrome. There is little English literature available on the latter. A review of the literature and a case report are presented here.